Question

Solve for n:|3n+5|=7

Answer 1

|f(x)|=7 implies f(x)=7 or f(x)=-7

Answer 2

You have two equations to solve

Answer 3

|3n+5|=7
(3n+5)^2 = 7^2
3n + 5 = sqrt(7^2)
3n+5 = 7
3n = 7-5
3n = 2
n = 2/3

Answer 4

It's like this
3n + 5 = 7
-5 -5
3n = 2
Divide both by 3 so "n" is alone
n=2/3

Answer 5

You have two equations to solve....

Answer 6

3n+5=7 or 3n+5=-7

Answer 7

You could do it the way @gerryliyana started off ...
square both sides... but you will get two solutions not one

Answer 8

or n = -4

Answer 9

i've not done anyway

Answer 10

\[(3n+5)^2=7^2 \\ (3n+5)(3n+5)=49 \\ 9n^2+15n+15n+25=49 \\ 9n^2+30n+25=49 \\ 9n^2+30n+25-49=0 \\ 9n^2+30n-24=0 \\ 3n^2+10n-8 =0\text{ divided both sides by 3 } \\ 3(-8)=(-12)(2)=(12)(-2) \text{ and } 12+(-2)=10 \\ 3n^2+12n-2n-8=0 \\ 3n(n+4)-2(n+4)=0 \\ (3n-2)(n+4)=0\]

Answer 11

then you know where to go from here