SOLUTION: I have a question Simplify by factoring. {{{sqrt(48a^2b)}}} Simplify {{{3 sqrt(-1/125)}}} Solve {{{sqrt(5x+21)=x+3}}}

Question 438741: I have a question
Simplify by factoring.
Simplify
Solve
Answer by unlockmath(1688) (Show Source): You can put this solution on YOUR website!
Hello,
I'll help you with the last one.
sqrt(5x+21)=x+3
First off we can square both sides to
5x+21=(x+3)^2
Expand this out:
5x+21=x^2+6x+9
Subtract 5x and 21 to get:
x^2+x-12=0
Factor
(x-3)(x+4)=0
Solve for x
x=3
x=-4
So we find that 3 works in the equation.
Make sense?
RJ
www.math-unlock.com
RELATED QUESTIONS
I need to simplify by factoring: sqrt... (answered by checkley77)

Simplify: sqrt (21) (sqrt(7) + sqrt(3)) a) 7 sqrt (3) + 3 sqrt(7) b) 7 sqrt(3) + sqrt (answered by Fombitz)

simplify 1/{{{ sqrt(3) }}} (answered by stanbon)

Simplify - Step by Step sqrt(7)+3,sqrt(98) sqrt(7)+3,sqrt(98) 21√2 +... (answered by Alan3354)

simplify {{{ (1 + sqrt(3)) / (1 - sqrt(3))... (answered by jokaehler)

how do i factor sqrt... (answered by oberobic)

Please Simplify: sqrt(3)/ (sqrt(3) +... (answered by lwsshak3)

Simplify by factoring. sqrt (x +... (answered by nerdybill)

Simplify by factoring. {{{sqrt((x +... (answered by bob123132)