Question

High School

Answer 1

Answer:

Step-by-step explanation:

6) y = 2x² +  6x - 80

1) y = 2*x² + 2*3x - 2*40

  y = 2 [ x² + 3x - 40]

2) Sum = 3

Product = -40

Factors = (-5) ; 8   {-5 +8 = 3  ; (-5)*8 = -40}

y = 2 [ x² + 8x - 5x - 40]

      = 2 [ x(x + 8) -  5(x + 8) ]

      = 2 [ (x +8) (x - 5)]

y = 2(x +8)(x -5)

b) y = 0

2(x + 8)(X - 5) = 0

x + 8 = 0 ;  x - 5 = 0

x = -8 ;             x = 5

(-8) ; 5  are the zeros.