Question

-4x+8y=40
-2x=y
solve by substitution

Answer 1

x=-20

Explanation:

• We know that y=-2x
• We substitute our Y into the main equation: -4x+8(-2x)=40
• Calculate: -4x-16x=40

-20x=40

• Switch the values to make x positive: -40 = 20x
• divide both sides by 20 to get x: -40÷20 = 20x÷20
• You should be left with: x=-20