Answer:
(- 1, 5 )
Step-by-step explanation:
Given the 2 equations
x + 2y = 9 → (1)
5x - y = - 10 → (2)
Multiplying (2) by 2 and adding to (1) will eliminate the y- term
10x - 2y = - 20 → (3)
Add (1) and (3) term by term to eliminate y
11x + 0 = - 11
11x = - 11 ( divide both sides by 11 )
x = - 1
Substitute x = - 1 into either of the 2 equations and solve for y
Substituting into (1)
- 1 + 2y = 9 ( add 1 to both sides )
2y = 10 ( divide both sides by 2 )
y = 5
solution is (- 1, 5 )
x + 2y = 9 x + 2y = 9
=====》
5x - y = - 10 (×2) 10x - 2y = - 20
+____________
11x + 0 = - 11
11x = - 11
x = - 1
Thus :
- 1 + 2y = 9
Add both sides 1
2y - 1 + 1 = 9 + 1
2y = 10
Divide both sides by 2
2y ÷ 2 = 10 ÷ 2
y = 5
_____________________________
