Question

3x+2y=23 1/2x-4=y What should I do for this one...? I dont really understand

Answer 1

Since you have y alone on one side of the equation......

Use substitution and plug in 1/2x-4 for y in the other equation.

$3x+2(1/2x-4)=23$

Distribute

$3x+x-8=23$

Combine like terms

$4x-8=23$

Add 8 to both sides

$4x=31$

Divide by 4

and $x=31/4$

Plug this value in for x

$31/4*1/2-4=y$

Simplify

$31/8-4=y$

Multiply everything by 8 and simplify

$31-32=8y\\-1=8y$

Divide.....

$y=-1/8$

Your answers are:

$y=-1/8\\x=31/4$