Question

6x + 3y = 9

2x + 3y = 1
Solve the system of equations.
A)
x = 2, y = -1
B)
x = -1, y = 2
C)
x=1/2,y=3
D)
x=3,y=-1/2
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Answer 1

A

Explanation:

Given the 2 equations

6x + 3y = 9 → (1)

2x + 3y = 1 → (2)

Subtracting the 2 equations term by term eliminates the y- term

Subtract (2) from (1) term by term, that is

(6x - 2x) + (3y - 3y) = 9 - 1

4x = 8 ( divide both sides by 4 )

x = 2

Substitute x = 2 into either of the 2 equations and evaluate for y

Substituting into (2)

2(2) + 3y = 1

4 + 3y = 1 ( subtract 4 from both sides )

3y = - 3 ( divide both sides by 3 )

y = - 1

The solution is x = 2, y = - 1 → A