Answer:
x = -1
y = 1
Explanation:
The system of equation is:
-7x + 2y = 9 ⇒ (1)
-4x - 7y = -3 ⇒ (2)
To solve the system multiply equation (1) by 7 and equation (2) by 2 to make the coefficients of y equal in values and different in signs, then add the two resulting equations to eliminate y and solve the new equation for x to find its value
∵ 7(-7x) + 7(2y) = 7(9)
∴ -49x + 14y = 63 ⇒ (3)
∵ 2(-4x) - 2(7y) = 2(-3)
∴ -8x - 14y = -6 ⇒ (4)
- Add equations (3) and (4)
∴ -57x = 57
- divide both sides by -57
∴ x = -1
Substitute the value of x in equation (1) or (2) to find y
∵ -7(-1) + 2y = 9
∴ 7 + 2y = 9
- Subtract 7 from both sides
∴ 2y = 2
- Divide both sides by 2
∴ y = 1