Math Question-help

I'd set up an algebraic equation like this:

15 + (4/3*15) + x + 3/4x = 77

Then solve:

35 + 7/4x = 77 ... because 15 + (20) is 35 and x + 3/4x is 7/4 x

7/4x = 42 ... because 77 - 35 is 42 and you're trying to isolate the variable

7x = 168 ... because 42 * 4 is 168

x = 24 ... because 168/7 is 24

So action game is $15, math game is $20, science game is $24 and strategy game is $18. Add them up and you get a total of $77.

It does seem a *bit* high level for a 5th grader, but it's good practice for them to start thinking algebraically.

I'd start with the action game since you know that's $15.
Since the math game costs 4/3 the action game, you know it costs $20.

That's $35 used up, leaving you $42 for the other two games combined.

The science game costs whatever it costs ... say $x, and the strategy game costs 3/4 of that so together they cost 7/4 of x. Divide 42 by 7 and you get that each 4th is $6, so the science title is $24 and the strategy game is $18.

That's not the only way to approach it, but it's definitely correct, and it relies on common sense rather than algorithms which is helpful when trying to help a child.

Side note... what does your 5th grader think about how to solve it. As a math teacher, I expect my students to be able to attempt their homework independently using what they've learned in class.

G= strategy game
S= Science title
M= math title
A = action game

A = $15
M= A x 4/3
G= 3/4 x S
77 - (A+M) = S + (3/4 x S)

So, A = $15
M = $20
A + M = $35
$77-$35 = $42

And since $42 = 7/4 x S then
S= $24 and G = $18

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ETA: What S.H. said, too. There are often multiple ways to solve problems. But your daughter's teacher is teaching a particular method, and likely wants her to use THAT method. If you don't know what that method is, then you need to find out.
Curious, though, did you and your husband solve it different ways AND get different solutions? Or just used different methods and got the same solution? Because, no matter what method you use, there is ONE correct answer.

My daughter is in 5th grade.
Now, per her curriculum and her Teacher... the Teacher wants the child to solve the math problem, by using the SCHOOL's method as it is taught.
So, even if my daughter for example, solves it another way (and they do have to show their work and every single step)... my daughter will get knocked for it... because, it is not the method, that they are taught IN class. Per math. They have to do it, using the steps that they are taught, in, class.
There have been times, my daughter did her math and got the right answer. BUT, because she did it in a varied way, and short cutted... she got it "wrong."

strategy game X = 3/4 Y

science game Y

Math M=4/3 of 15

Action A=15

A+X+Y+M=77

15+(3/4Y)+Y+(4/3*15)=77

15+1 3/4Y+20=77
1 3/4 Y = 77-15-20
1 3/4 Y = 42
1.75Y/1.75 = 42 / 1.75
Y = 24

science game: $24
Startegy game 3/4 of 24 = 18
Math game 4/3 of 15 = 20
Action game = 15

And then there is real life . . .

A Honda gets 38 mpg. $25,000
A Chevy gets 40 mpg $10,000
A Hundai gets 43 mpg $11,000
A Prius gets 55 mpg. $30,000
Gas is $3.50 a gallon.

Which one is the best deal? How many miles will you have to drive before the Prius becomes the best deal?

Good luck to you and yours.

Ah, you have come to the right place!!
So, you know that the sum of all 4 software is 77. What you need to do is determine what each one costs.
So I always set up a "list" of my variables... Sometimes my variables have real values, sometimes they are "x" & sometimes they are ratios of either real values or "x".

Here is what we know:
Action = $15
Math = 4/3 * $15
Strategy = 3/4 * Science
Science = ??

We don't know the value of Science, so we will call that "X", which makes the value of Strategy = 3/4 * X

So your expression will be:
77 = X + 3/4X + 15 + 4/3(15)

Imagine that X is really the same as 1 times X. You now have 1X & 3/4X. Togther they make 1 3/4 X.
You can also combine the non-X items on the right side. 4/3 times 15 = 20. 20 + 15 = 35.

77 = 1 3/4X + 35

Now, you will subtract 35 from both sides to isolate the X variable. This gets rid of it on the right side, & reduces your value on the left.

42 = 1 3/4X

Knowing that 1 3/4 is the same as 1.75, divide both sides by that amount to get X alone, & you will find:

24 = X

Now, plug 24 into your original equation wherever you had X to find the value of all the software titles.

Hope this helps! T.

P.S. I am taking a Physics course, & find that it is helpful to make my "list" of what I know, what I don't know & what known relationships I have so that everything is laid out when I begin difficult problems. Not sure if that is something your child's teacher will approve of, but if so, it does help when you get into more complicated expressions, & need to solve with more than one unknown variable (X & Y) where you begin to use substitutions to isolate values.

Action = 15.
Math = (4*15)/3 = 20
15+20 = 35
77-35 = 47
Science = x
Strategy = 3/4 * x

x + 3/4x = 47
7/4x = 47
x = science = 47*4/7 = 24
strategy = 3/4 * x = 3/4 * 24 = 18

Hmmm

All *I* can say is that several people have 'solved' for the equation...and all came up with different answers...

lol

Did anyone account for 'discounts' or 'points' from the store purchased??

A 'membership' card?

Taxes?

OY!!

lol

I will be interested to hear a 'correct' answer...

DO post back!

_____________________________________________________________

*ETA

Upon closer inspection...there were some equal answers...

MEA CULPA

I am really NO help to my kiddos with regard to math***

OMG! Stop before my head explodes!!! I'm having flashbacks to algebra classes that I never did well in! I will never be able to help my kids with math homework!

And to 8kidsdad: Dont forget to factor in the average need for repairs for each make and model, cost of parts, ability to do work yourself or cost to have it done, which on average is the longest lasting vehicle and the resale value if you are not going to hand it down to your child. I choose the Toyota Matrix at 39 mpg, slightly used at $15,400. :)

You go to the teacher and let her know that if this problem causes this much stress from two educated people, that it is way too advanced for 5th grade homework. Some teachers are still stuck in the stone ages. This type homework is senseless.

I hate word problems. I never saw my first one until 9th grade. It was all downhill from there...

So sorry for all three of you!

Action = $15
Strategy = 3/4 Science
Math = 1+1/3 Action.
Science = x

So math =$15+ $5 = $20
So... 20+(3/4 x X) = 77
Solve for X...let's see

You want to isolate X to solve so first divide both sides of the equation by 20

3/4 x X = 77/20

so 3/4 x X = 3.85

3/4 is the same at 0.75, so divide both side by 0.75
x = 5.1333333333333

Huh....
5.13
20
15

this isn't going to add up to $77...

5th grade?