F(x) = x² + x - 20 = x² + 5x - 4x - 20 = x(x + 5) - 4(x + 5) = (x + 5)(x - 4)
f(x) = 0 ⇔ (x + 5)(x - 4) = 0 ⇔ x + 5 = 0 or x - 4 = 0 ⇒ x = -5 or x = 4
Answer: C. x = -5 and x = 4.
Answer:
327648835 is the answer....
we have that

I. Rewrite the equation by substituting the expression u in for sin x.

II. Factor the quadratic expression. Rewrite the equation with factors instead of the original polynomial.
is equal to
using a graph calculator-----> see the attached figure

III. Use the zero product property to solve the quadratic equation.

(u-3)=0--------------> u=3
(2u+1)=0-------- 2u=-1------> u=-1/2-----> u=-0.5
IV. Rewrite your solutions to Part III by replacing u with sin x.
sin x=3--------> is not the solution (sin x can not be greater than 1)
sin x=-0.50------>is the solution
V. Solve the remaining equations for x, giving all solutions to the equation.
sin x=-0.50
if the sine is negative
then
x belong to the III or IV quadrant
we know that
sin 30°=0.50
so
the solution for the III quadrant is
x=180°+30°-------> x=210°
the solution for the IV quadrant is
x=360°-30°------> x=330°
Answer:
C.
Step-by-step explanation:
Jack's rate = 28/2 = 14 boxes/hour
Walter's rate = 36/3 = 12 boxes/hour
Combined rate = 14 + 12
= 26 boxes/hour
26 = 65/t
26t = 65