Factor the following equations:
a) 9x^3 + 35x^2 - 4x
b) 6x^2 + 5x - 4
I'll do #1, you try #2 on your own. These, by the way, are not equations. (there is no = or right hand side) These are expressions.
To "factor" is to take the greatest common element among each of the terms and then divide it out from the expression.Originally Posted by soni
Now, each of these terms all have an x in common, so let's pull that out first. (in general, factor out the highest possible degree of x first)
9x^3 + 35x^2 - 4x
x (9x^2 + 35x - 4)
What is left in the brackets? We can no longer pull another x out since the last term has no x's left. This is a quadratic. Use the quadratic formula to factor.
it into (9x-1)(x+4). (solutions if plugged into the quadratic equation are 1/9 and -4, the "zeroes" of the quadratic if it were an equation set to = 0)
so the remaining expression is x(9x-1)(x+4)