Question

solve the simultaneous equations
3x-y=18
2x+y=7
answer x=
y=

Answer 1

3x -y= 18 (1)
2x +y = 7 (2)

Take (1)+ (2):
(3x+2x)+ (-y+y)= 18+7
⇒ 5x = 25
⇒ x= 25/5
⇒ x=5

Use (2) to find y:
2*5+y= 7
⇒ 10+y=7
⇒ (10-10)+y= 7-10
⇒ y = -3

Final answer:
x=5, y=-3.

Hope this helps~