SOLUTION: The hypotenuse of a right triangle measures 20cm. The sum of the lengths of the other 2 sides is 28cm. Find the lengths of these two sides. x(squared) + (28 - x)(squared)

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: The hypotenuse of a right triangle measures 20cm. The sum of the lengths of the other 2 sides is 28cm. Find the lengths of these two sides. x(squared) + (28 - x)(squared)       Log On


   



Question 185852: The hypotenuse of a right triangle measures 20cm. The sum of the lengths of the other 2 sides is 28cm. Find the lengths of these two sides.
x(squared) + (28 - x)(squared) = 20(squared)
Let x be the length of one side. Therefore the length of the other side is 28 – x.

Found 2 solutions by solver91311, edjones:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!



You have your equation already:





Standard form:



Divide by 2:



Factor and solve. Either root can be x and the other will be 28 - x.

John


Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
c=20, a+b=28
a^2+b^2=c^2
x^2+(28-x)^2=20^2
x^2+x^2-56x+784=400
2x^2-56x+384=0
2(x^2-28x+192)=0
x^2-28x+192=0
x=12, x=16 these are the two sides.
.
Ed
.
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B-28x%2B192+=+0) has the following solutons:

x%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=%28-28%29%5E2-4%2A1%2A192=16.

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

x%5B1%5D+=+%28-%28-28%29%2Bsqrt%28+16+%29%29%2F2%5C1+=+16
x%5B2%5D+=+%28-%28-28%29-sqrt%28+16+%29%29%2F2%5C1+=+12

Quadratic expression 1x%5E2%2B-28x%2B192 can be factored:
1x%5E2%2B-28x%2B192+=+%28x-16%29%2A%28x-12%29
Again, the answer is: 16, 12. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-28%2Ax%2B192+%29