SOLUTION: Hey, how would you solve: 3.5*10^-6(15-s)^2=2.5*10^-6*s^2 i know the answer is 0.3s^2 - 30s + 225 = 0 but how do i get here? Thanks, its appreciated, Zane

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Hey, how would you solve: 3.5*10^-6(15-s)^2=2.5*10^-6*s^2 i know the answer is 0.3s^2 - 30s + 225 = 0 but how do i get here? Thanks, its appreciated, Zane      Log On


   

Question 899375: Hey, how would you solve:
3.5*10^-6(15-s)^2=2.5*10^-6*s^2
i know the answer is 0.3s^2 - 30s + 225 = 0
but how do i get here?
Thanks, its appreciated,
Zane
Found 2 solutions by Fombitz, ewatrrr:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
3.5%2A10%5E%28-6%29%2815-s%29%5E2=2.5%2A%2810%5E-6%29%2As%5E2
Divide both sides by 10%5E%28-6%29
3.5%2A%2815-s%29%5E2=2.5%2As%5E2
%287%2F2%29%2815-s%5E2%29=%285%2F2%29s%5E2
Multiply both side by 2
7%2815-s%29%5E2=5s%5E2}
7%28225-30s%2Bs%5E2%29=5s%5E2
1575-210s%2B7s%5E2=5s%5E2
highlight%282s%5E2-210s%2B1575=0%29
That's not the same answer as the one you stated.
Your given answer would be (multiplying the equation by 20%2F3 to match the leading coefficient),
2s%5E2-200s%2B1500=0


Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
+%283.5%2F10%5E6%29%28225+-+30s+%2B+s%5E2%29+=+%282.5%2F10%5E6%29s%5E2%29
+%28%283.5%2F10%5E6%29%2F%282.5%2F10%5E6%29%29%28225+-+30s+%2B+s%5E2%29+=+s%5E2
+%281.4%29%28225+-+30s+%2B+s%5E2%29+=+s%5E2
.4s^2 - 42s + 315