Question

Solve by multiplication and addition. Show each step of your work. 2x – 3y = 18 4x + y = 8 Please help me!!!! I am giving 50 points!

Answer 1

2x - 3y = 18
4x + y = 8
/*multiply first eqtn by -2

-4x + 6y = -36
4x + y = 8
/*add the eqtns

-4x + 6y + 4x + y = -36 + 8
7y = -28
y = -4

Plug in the y value into either of the first two eqtns:

2x - 3*(-4) = 18
2x +12 = 18
2x = 18 - 12
2x = 6
x = 3

(x,y)=(3,-4)

Answer 2

(x, y ) = (3 , - 4 )

Explanation:

given the 2 equations

2x - 3y = 18 → (1)

4x + y = 8 → (2)

multiply (2) by 3

12x + 3y = 24 → (3)

add (1) and (3) term by term to eliminate the term in y

(2x + 12x) + (- 3y + 3y) = (18 + 24)

14x = 42 ( divide both sides by 14 )

x = 3

substitute x = 3 in (1) or (2) to evaluate for y-coordinate

(2) → 12 + y = 8 ⇒ y = 8 - 12 = - 4

solution is (3, - 4 )