^2= squared
2006-11-03 06:25:57 · 8 answers · asked by Math Freak 1990 1 in Science & Mathematics ➔ Mathematics
First put everything on one side:
m² - 2m - 15 = 0
Now figure the factors of -15:
-1, 15
-3, 5
-5, 3
-15, 1
You need the pair that will have a sum of -2 (the coefficient of your x-term). That would be -5 and 3.
(m - 5)(m + 3) = 0
2006-11-03 06:28:42 · answer #1 · answered by Puzzling 7 · 1⤊ 0⤋
m^2 - 2m = 15 (Subtract 15 from both sides)
m^2 - 2m - 15 = 0 (Factor)
(m - 5)(m + 3) = 0
m - 5 = 0 or m + 3 = 0
m = 5 or m = -3
QED
2006-11-03 18:30:09 · answer #2 · answered by CSUFGrad2006 5 · 0⤊ 0⤋
m^2 - 2m - 15 = 0
m^2 -5m + 3m - 15 = 0
m(m-5) + 3(m-5) = 0
(m-5)(m+3) = 0
=> m - 5 = 0 or m + 3 = 0
Therefore m = 5 or -3
2006-11-03 14:29:59 · answer #3 · answered by Maddy 1 · 0⤊ 0⤋
Put in standard form:
m^2-2m-15=0
what numbers when multiplied give you -15 and when added give you -2?
How about -5 and +3?
2006-11-03 14:28:28 · answer #4 · answered by modulo_function 7 · 0⤊ 0⤋
m^2 - 2m = 15
m^2-2m-15=0
(m-5)(m+3)=0
m-5=0
m=5
m+3=0
m=-3
2006-11-03 15:09:27 · answer #5 · answered by yupchagee 7 · 0⤊ 0⤋
m^2 - 2m - 15 = 0
m^2 + 3m - 5m - 15 = 0
m(m+3) - 5(m+3) = 0
(m-5)*(m+3) = 0
m = 5 or m = -3
2006-11-03 14:27:18 · answer #6 · answered by spoof ♫♪ 7 · 0⤊ 0⤋
(x-5) * (x+3) = 0
2006-11-03 14:30:30 · answer #7 · answered by bergab_hase 3 · 0⤊ 0⤋
m^2-2x-15=0
x^2-5x+3x-15=0
x(x-5)+3(x-5)=0
m-5=0 or x+3 = 0
x=5 or x=-3
2006-11-03 14:28:15 · answer #8 · answered by Anonymous · 0⤊ 0⤋