SOLUTION: There are two distinct solutions x to the equation 18+5x^2=20x. If each solution is rounded to the nearest integer, and then these two integers are multiplied together, what is the

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: There are two distinct solutions x to the equation 18+5x^2=20x. If each solution is rounded to the nearest integer, and then these two integers are multiplied together, what is the      Log On


   

Question 1086043: There are two distinct solutions x to the equation 18+5x^2=20x. If each solution is rounded to the nearest integer, and then these two integers are multiplied together, what is the result?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

18%2B5x%5E2=20x
5x%5E2-20x%2B18=0
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-%28-20%29+%2B-+sqrt%28+%28-20%29%5E2-4%2A5%2A18+%29%29%2F%282%2A5%29+
x+=+%2820+%2B-+sqrt%28+400-360%29%29%2F10+
x+=+%2820+%2B-+sqrt%28+40%29%29%2F10+
x+=+%2820+%2B-+2%2Asqrt%2810%29%29%2F10+
x+=+%28cross%2820%2910+%2B-+cross%282%29%2Asqrt%2810%29%29%2Fcross%2810%295+
x+=+%2810+%2B-+sqrt%2810%29%29%2F5+
x+=+%2810%2F5+%2B-+sqrt%2810%29%2F5%29+
x+=+%282+%2B-+sqrt%2810%29%2F5%29+
solutions:
x+=+%282+%2B+sqrt%2810%29%2F5%29+
x+=+%282+%2B+3.162277660168379%2F5%29+
x+=+2+%2B+0.6324555320336759+
x+=+2.6324555320336759+...rounded to the nearest integer is
x+=+3+
or
x+=+%282+-+sqrt%2810%29%2F5%29+
x+=+%282-+3.162277660168379%2F5%29+
x+=+2+-+0.6324555320336759+
x+=+1.3675444679663241+...rounded to the nearest integer is
x+=+1+

then, when these two integers are multiplied together, the result is
3%2A1=3+