Verified answer

1)

(x - 5)(x + 4) = 0

x = 5 , x = - 4

2)

14x² - 15x - 9 = 0

(7x + 3)(2x - 3) = 0

x = - 3/7 , x = 3/2

standard form of quadratic equations:

ax^2+bx+c=0

1)

x^2 - x - 20 = 0

a=1

b=-1

c=-20

find the factors of 20

which set of factors add up to to -1

-5, 4

(x-5)(x+4)=0

set both equations equal to 0

x-5=0

x=5

x+4=0

x=-4

{5,-4}

2)

x(14x - 15) = 9

14x^2-15x-9=0

(2x-3)(7x+3)=0

2x-3=0

x=3/2

7x+3=0

x=-3/7

{3/2, -3/7}

a million.) x^2 - 4*x + 4 - 3*x + 6 + 2 = 0 combine like words: x^2 - 7*x + 12 = 0 component the polynomial on the left of the "=" (x- 4)*(x - 3) = 0 This equation potential that the two (x-4) or (x - 3) equivalent 0. x = 4 and/or x = 3