Question

Solve the following system of equations:

2x + 4y = 18

-3x + 2 = y

A.(-1, 4)

B.(1, 4)

C.(-1, 5)

D.(1, -1)

Answer 1

Option C

Explanation:

Given the following question:


`2x+4y=18`

`-3x+2=y`

To find the answer we need to find the values of each of the variables by solving one equation at a time, and then substitute those answers into each equation in till we have our answers.


`2x+4y=18`

`-3x+2=y`

`y-y=0`

`-3x+2+ -y=0`

`2-2=0`

`-3x+-y=0+-2`

`-3x+3x=0`

`-y=3x-2`

`-y/-1=y`

`3x+2/-1=-3x+2`

`y=-3x+2`

Substitute y for -3x + 2:

`2x+4y=18`

`y=-3x+2`

`2x+4(-3x+2)=18`

`2x+4(-3x+2)=18=-10x+8=18`

`-10x+8=18`

`8-8=0`

`18-8=10`

`-10x=10`

`-10x/10=x`

`10/-10=-1`

`x=-1`

Substitute x for -1:

`y=-3x+2`

`x=-1`

`y=-3(-1)+2`

`-3*-1=3`

`y=3+2`

`3+2=5`

`y=5`


`x=-1`

`y=5`

Your answer is "(-1, 5)" or option C.

Hope this helps.