Question

Help please...........1. y = 3 x y = -8x2. y = - 7x y =-4x - 12

Answer 1

1. -8x = 3x

-11x = 0

x= 0

y= 3(0)= 0

(0, 0)

2. -7x = -4x - 12

-3x = -12

x = 4

y = -7(4)= -28

(4, -28)

Answer 2

(1)

both equations express y in term of x, hence equate the right sides

- 8x = 3x ( subtract 3x from both sides )

- 11x = 0 ( divide both sides by - 11 )

x = 0

substitute x = 0 into y = 3x → y = 0

solution is : (x, y ) → (0, 0)

(2)

both equations express y in terms of x, hence equate the right sides

- 4x - 12 = - 7x ( add 7x to both sides )

3x - 12 = 0 ( add 12 to both sides )

3x = 12 ( divide both sides by 3 )

x = 4

substitute x = 4 into y = - 7x → y = - 28

solution is : (x, y ) = (4, - 28 )