2007-04-27 19:30:53 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
(x-10)(x+9)
x=10,-9
2007-04-27 19:33:29 · answer #1 · answered by Anonymous · 0⤊ 0⤋
ax^2+bx+c=0
x^2- x - 90 = 0
so find all factors of the constant (i.e.90)
2*45, 3*30...56*15, 9*10.
so, in all, only, 10-9 = 1 which is the b value in the equation.
Hence,
(x-10)
(x+9)
(x-10)(x+9) = 0
so, x-10 = 0 or x+9=0
x= 10 or x = -9
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2007-04-28 03:14:20 · answer #2 · answered by Kuan T 2 · 0⤊ 0⤋
x^2 - x - 90
=x^2 + 9x - 10x - 90
=x(x + 9 ) - 10(x + 9)
=(x + 9)(x - 10)
2007-04-28 02:44:57 · answer #3 · answered by billako 6 · 0⤊ 0⤋
(x + ?)(x + ?) = 0
You have to determine what two numbers multiply to make
-90 (the constant term) and add to make -1 (the coefficient of x). In our case, it's -10 and +9. That's what goes in the question marks.
(x - 10)(x + 9) = 0
Therefore,
x = {10, -9}
2007-04-28 02:34:07 · answer #4 · answered by Puggy 7 · 0⤊ 0⤋
(x - 10).(x + 9) = 0
x = 10, x = - 9
2007-04-28 03:58:05 · answer #5 · answered by Como 7 · 0⤊ 0⤋
(x-10)(x+9)=0
x=10 or -9
2007-04-28 02:34:15 · answer #6 · answered by raj 7 · 0⤊ 0⤋
x^2-x=90
and go from there.
2007-04-28 02:38:34 · answer #7 · answered by Anonymous · 0⤊ 1⤋