*Solving Quadratic Equation By Factoring* B2 + 4b - 21 = 0

*solving quadratic equation by factoring* b2 + 4b - 21 = 0

 

Answer:

(b+7)(b-3)

Step-by-step explanation:

Since the sum is 4, and the product is -21, we should think of 2 numbers that satisfies the following conditions.

7 and -3 are the factors, since when we add them, we get 4.

7 + (-3) = 4

When we multiply them, we get

7 x (-3) = -21

Therefore, we get the following factors:

(b+7)(b-3).