I got (0,-1,-7) but I lack confidence.
2007-05-01 04:06:29 · 4 answers · asked by dprut 2 in Science & Mathematics ➔ Mathematics
3x^3-24x^2+21x=0
3x(x^2-8x+7)=0
3x(x-7)(x-1)=0
x = 0, +7, +1
watch the signs. -7x+(-x)=-8x
(-7)(-1)=+7
2007-05-01 04:12:10 · answer #1 · answered by jaybee 4 · 1⤊ 0⤋
first factor the equation to x(3x^2-24x+21)=0
factor again to get x(3x-3)(x-7)=0
so x=0 3x-3=0 and x-7=0
so the solutions are 0, 1 and 7
2007-05-01 04:11:06 · answer #2 · answered by sharkey 4 · 0⤊ 0⤋
3x^3-24x^2+21x=0
You can factor 3x
3x(x^2-8x+7)=0
And the quadratic term can be factored
x^2-8x+7=(x-7)(x-1)
So you have 3x(x-7)(x-1)=0 so x=0, x=7, x=1
2007-05-01 04:14:35 · answer #3 · answered by Astral Walker 7 · 1⤊ 0⤋
First factor out the x: x(3x^2-24x+21)=0, then factor the rest to get x(3x-3)(x-7). So your answers are x=0,1,7.
2007-05-01 04:10:24 · answer #4 · answered by bruinfan 7 · 0⤊ 0⤋