Question

What is the x value for the system of equations?
2x + 3y = 4
x - 2y = -5

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I got y = 2 but when i put that into the first equation I ended up with x = 0. However, my answer choices are -1, 1, 2, and -2

Answer 1

you can use substitution method

1. find the value of y in terms of x from 2nd equation and tell what you get ?

Answer 2

We want the 'x' value? okay....so lets solve that top equation for 'y'

2x + 3y = 4

subtract 2x from both sides

3y = -2x + 4

divide everything by 3

y = -2/3x + 4/3


Now substitute this in for 'y' in that second equation

x - 2y = -5

Will become

x - 2(-2/3x + 4/3) = -5

distribute the -2

x + 4/3x - 8/3 = -5

Add 8/3 to both sides

x + 4/3x = -5 + 8/3

well
x + 4/3x = 7/3x

and
-5 + 8/3 = -7/3

So we have

7/3x = -7/3

x = -1 is what I get

*elimination method here would have been easier*

Answer 3

2x + 3y = 4 -->(2)
x - 2y = -5 --> (3)
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4x + 6y = 8 (result of multiplying by 2)
3x - 6y = -15 (result of multiplying by 3)
------------add
7x = -7
x = -1