Question

how do you solve 3|2a + 7| =3a + 12

Answer 1

first you need to break the modulus
their will be two cases
2a + 7 >= 0 and 2a + 7 < 0
then you solve for a in both the cases
and check if the solution satisfies the inequality above (case you are solving)
if it satisfies then it counts as a valid solution

all valid solutions is the final solution

Answer 2

http://www.wolframalpha.com/input/?i=3 |2a+%2B+7|+%3D3a+%2B+12

Answer 3

3|2a + 7| =3a + 12
i.e.\[ |2a + 7| =\frac{3a + 12}{3} \rightarrow |2a + 7| = a+4\]
\[2a + 7 = \pm (a+4)\]
\[2a + 7 = (a+4) or 2a + 7 = - (a+4)\]
\[2a + 7 = a+4 or 2a + 7 = - a-4\]
\[2a -a = 4-7 or 2a + a = - 7-4 \rightarrow a =-3 or 3a= -11 \]
\[a =\frac{-11}{3},-3 \]

Answer 4

thnk you so much :D