Answer:
x = - 5, x = 4
Step-by-step explanation:
Given
f(x) = x² + x - 20
To find the zeros equate f(x) to zero, that is
x² + x - 20 = 0
Consider the factors of the constant term ( - 20) which sum to give the coefficient of the x- term ( + 1)
The factors are + 5 and - 4, since
5 × - 4 = - 20 and + 5 - 4 = + 1, hence
(x + 5)x - 4) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 5 = 0 ⇒ x = - 5
x - 4 = 0 ⇒ x = 4
The 3 inside angles of a triangle need to add up to 180 degrees.
You have two angles of 104 and 36.
A = 180 - 104 - 36 - 40
The answer is 40
