Algebra 1

-45

"If (3m+4)^2=169 but m<0 what is the value of m"

(3m+4)^2=169 |sqrt()
<=> 3m+4=+/- 13 *
<=> 3m = -4 +/- 13
<=> m = (-4 +/- 13)/3
<=> m=(-4-13)/3 of m= (-4+13)/3
<=> m=-17/3 of m=3

sinse m<0: m=3 isn't valid answere
m=-17/3

* when x^2=a where a >= 0
x can be either + or - square root of a, because both (+/- sqrt(a))^2 are just a

22543's answer is really good but it might be easier for you if you split it into 2separate equations when you take the square root.

3m+4=13 OR 3m+4=-13

then solve each one separately and at the end choose the answer/s that meet the condition m<0