SOLUTION: Write a quadratic equation having the given numbers as solutions. -10/3,-9/5 A) 15x2 + 77x +90=0 B) 15x2 + 6x + 77=0 C) 15x2 - 77x + 90=0 D) 15x2 + 77x -90=0 E) 15x2 + 77

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Write a quadratic equation having the given numbers as solutions. -10/3,-9/5 A) 15x2 + 77x +90=0 B) 15x2 + 6x + 77=0 C) 15x2 - 77x + 90=0 D) 15x2 + 77x -90=0 E) 15x2 + 77      Log On


   

Question 721579: Write a quadratic equation having the given numbers as solutions.
-10/3,-9/5
A) 15x2 + 77x +90=0
B) 15x2 + 6x + 77=0
C) 15x2 - 77x + 90=0
D) 15x2 + 77x -90=0
E) 15x2 + 77x +6=0
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
If a fraction, n%2Fd is a solution then (d*x+n) is a factor. So if %28-10%29%2F3 and %28-9%29%2F5 are solutions, then (3x+(-10)) and (5x+(-9)) (or (3x-10) and (5x-9)) are factors. So the quadratic equations that will have the given solutions will have the form:
a(3x-10)(5x-9) = 0 (where "a" is any non-zero number)

Use FOIL to multiply (3x-10)(5x-9). You will get one of the 5 possible answers given. (This means the "a" must be 1. If you had not gotten one of the 5 answers, you would multiply what you did get by different a's (2, -3, 1/5, etc.) until you got a match.)