SOLUTION: the book says to solve by factoring and using the principle of zero products: x2+4x-21=0 how do you do this?

Question 371342: the book says to solve by factoring and using the principle of zero products:

x2+4x-21=0
how do you do this?
Answer by ewatrrr(24785) (Show Source): You can put this solution on YOUR website!



Hi,

solve by factoring and using the principle of zero products

x^2+4x-21=0

factoring

(x+7)(x-3) = 0  Note: the SUM of the outer product,-3x and inner product,7x = 4x

using the principle of zero products

(x+7= 0

x = -7

(x-3) = 0

x = 3 

RELATED QUESTIONS

Solve by factoring and using the principle of zero products.

x2 + 6x - 16 = 0... (answered by Alan3354,stanbon)
Solve by factoring and using the principle of zero products:... (answered by Alan3354)
Solve by factoring and using the principle of zero products:
 x^2 + 4x - 21 = 0
 (answered by jsmallt9)
	Solve by factoring and using the principle of zero products:
 x^2+4x-21=0

 (answered by lynnlo)
Solve by factoring and using the principle of zero products.

x2 - 7x = 0 
 (answered by College Student)
 Solve by factoring and using the principle of zero products. Show work
x2 - 7x = 0
i... (answered by mananth)
Solve by factoring and using the principle of zero products... (answered by ewatrrr)
can you help me
solve by factoring and using the principle of zero products... (answered by anantha)
Solve by factoring and using the principle of zero products. Show all work necessary.... (answered by Fombitz)