SOLUTION: I need help with this problem:Ten years ago, Mr.Brown was as old as Mrs.Brown is now, whereas Mrs.Brown was at that time only half as old as Mr. Brownis now. Find ther present ages

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Question 409177: I need help with this problem:Ten years ago, Mr.Brown was as old as Mrs.Brown is now, whereas Mrs.Brown was at that time only half as old as Mr. Brownis now. Find ther present ages of Mr.Brown and Mrs.Brown.
Answer by Jeef Gorrdon(26) About Me  (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ayourfatcan%5E2%2Bbyourfatcan%2Bc=0 (in our case 1yourfatcan%5E2%2B-2yourfatcan%2B-3+=+0) has the following solutons:

yourfatcan%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=%28-2%29%5E2-4%2A1%2A-3=16.

Discriminant d=16 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--2%2B-sqrt%28+16+%29%29%2F2%5Ca.

yourfatcan%5B1%5D+=+%28-%28-2%29%2Bsqrt%28+16+%29%29%2F2%5C1+=+3
yourfatcan%5B2%5D+=+%28-%28-2%29-sqrt%28+16+%29%29%2F2%5C1+=+-1

Quadratic expression 1yourfatcan%5E2%2B-2yourfatcan%2B-3 can be factored:
1yourfatcan%5E2%2B-2yourfatcan%2B-3+=+1%28yourfatcan-3%29%2A%28yourfatcan--1%29
Again, the answer is: 3, -1. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-2%2Ax%2B-3+%29