SOLUTION: solve: 15m(m+5)=46m-12

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Question 950627: solve: 15m(m+5)=46m-12
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
15m(m+5)=46m-12
15m%5E2%2B75m=46m-12 Subtract 46m from each side.
15m%5E2%2B29m=-12 Add 12 to each side.
15m%5E2%2B29m%2B12=0
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation am%5E2%2Bbm%2Bc=0 (in our case 15m%5E2%2B29m%2B12+=+0) has the following solutons:

m%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%2829%29%5E2-4%2A15%2A12=121.

Discriminant d=121 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-29%2B-sqrt%28+121+%29%29%2F2%5Ca.

m%5B1%5D+=+%28-%2829%29%2Bsqrt%28+121+%29%29%2F2%5C15+=+-0.6
m%5B2%5D+=+%28-%2829%29-sqrt%28+121+%29%29%2F2%5C15+=+-1.33333333333333

Quadratic expression 15m%5E2%2B29m%2B12 can be factored:
15m%5E2%2B29m%2B12+=+15%28m--0.6%29%2A%28m--1.33333333333333%29
Again, the answer is: -0.6, -1.33333333333333. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+15%2Ax%5E2%2B29%2Ax%2B12+%29

ANSWERS:-0.6,-1.33