Question

What is the value of the y variable in the solution to the following system of equations?
5x + 4y = 1
4x + 3y = -1

A -7

B 7

C 9

D -9

Answer 1

I don't know how to do it that's why I need the answers

Answer 2

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Answer 3

Lame

Answer 4

I won't give you answer but I can give you hints on how to solve this.

Answer 5

5x + 4y = 1..................................1
4x + 3y = -1.......................2

From equation 1
5x=1-4y
x=1-4y/5 now put into 2nd equ then get value of y .
After getting value of y then put into 1st equ to get value of x.

Answer 6

Example:

5x+y=31 [1]
x-2y=-7 [2]

rearrange [1] to make y the subject.
y = 31 - 5x
rearrange [2] to make y the subject.
-2y = -7 - x
2y = 7 + x
y = (7 + x)/2

Now equate your two expressions for y.

31 - 5x = (7+x)/2
2(31 - 5x) = 7 + x
62 - 10x = 7 + x
55 = 11x
therefore x = 5

Now sub in x = 5 into [1] or [2] (doesn't matter)
[2] -> (5)-2y = -7
-2y = -12
2y = 12
y = 6

So there you have it...
x = 5, y = 6.

Now follow my approach on your problem

Answer 7

Another approach could be the following:
If you multiply the 1st equation by 4 and the second equation by 5, you'll get two equations that both have 20x in them.
You can isolate 20X on both and then combine to get a single equation with only Y as the unknown (which is what you're solving for)

Answer 8

do you need help