Find x Solve the simultaneous equations 3x + 2y = 27 3x – y=9
1 answer:
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Answer:
D
Step-by-step explanation:
The equations are
● 4x + 2y = 10 (1)
● 4x - 2y = -10 (2)
● 4x + 2y = 10
Add - 4x to both sides
● 4x + 2y -4x = 10 -4x
● 2y = 10 -4x
Divide both sides by 2
● 2y/2 = (10 - 4x)/2
● y = 5 - 2x
● y = -2x + 5 (1)
● 4x - 2y = -10
Add -4x to both sides
● 4x -2y -4x = -10 - 4x
● -2y = -10 - 4x
Divide both sides by -2
● -2y/-2 = (-10 -4x)/-2
● y = 10 + 2x
● y = 2x + 5 (2)
So the equation are
● y = 2x + 5
● y = -2x + 5
Graph them
The lines intersect at (0,5) but aren't perpendicular
So the answer is d
