Question

X-3y - 5=0 dan 2x -5y =9. Nilai dari 3x + 2y adalah?

Answer 1

X - 3y - 5 = 0 | x2 | 2x - 6y - 10 = 0
2x - 5y = 9    | x1 | 2x - 5y -9 = 0

-y -1 = 0
-y = 1
y = -1

x - 3y - 5 = 0
x - 3 (-1) - 5 = 0
x + 3 - 5 = 0
x - 2 = 0
x = 2

nilai 3x + 2y = 3 . 2 + 2 (-1) = 6 - 2 = 4

Answer 2

X - 3y = 5  |*2  | 2x - 6y = 10
2x - 5y = 9 | *1| 2x - 5y = 9
⇒ -y = 1
⇒ y = -1
x - 3y = 5
x - 3(-1) = 5
x + 3 = 5
x = 2.

3x + 2y = 3(2) + 2(-1) = 6 - 2 = 4.