SOLUTION: square root of 144 + 3[8+7(2-3)]= I can't seem to get the right answer which is 15

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: square root of 144 + 3[8+7(2-3)]= I can't seem to get the right answer which is 15      Log On


   

Question 86672: square root of 144 + 3[8+7(2-3)]= I can't seem to get the right answer which is 15
Answer by bucky(2189) About Me  (Show Source):
You can put this solution on YOUR website!
Given:
.
sqrt%28144%29+%2B+3%288%2B7%282-3%29%29=+y
.
Find y
.
First you can do sqrt%28144%29+=+12. Substitute this and the equation becomes:
.
12+%2B+3%288%2B7%282-3%29%29+=+y
.
Now start with the most nested (the interior) set of parentheses. These are the parentheses
that contain 2 - 3. Since 2 - 3 = -1 we can substitute this and the equation becomes:
.
12+%2B+3%288%2B7%28-1%29%29+=+y
.
Then multiply 7 times the -1 and get -7. Substitute -7 for 7(-1) and the equation then
becomes:
.
12+%2B+3%288+-+7%29+=+y
.
Then subtract 7 from 8 to get +1. Substitute +1 for the parentheses and you have:
.
12+%2B+3%28%2B1%29+=+y
.
Multiply 3 times +1 and the equation is reduced to:
.
12+%2B+3+=+y
.
and the answer (y) is equal to 12 + 3 and this is +15
.
Hope this explains where the answer came from.