Question

Solve the following pairs of simultaneous equations involving two unknowns. 1 . x+y=8x-y=21

Answer 1

x = 14.5 , y = - 6.5

Explanation:

given the simultaneous equations

x + y = 8 → (1)

x - y = 21 → (2)

adding (1) and (2) term by term will eliminate y

(x + x) + (y - y) = 8 + 21

2x + 0 = 29

2x = 29 ( divide both sides by 2 )

x = 14.5

substitute x = 14.5 into (1) and solve for y

14.5 + y = 8 ( subtract 14.5 from both sides )

y = - 6.5

solution is x = 14.5 , y = - 6.5