Posted by Liz on .
I don't know how to solve 12x(2)-15x=0 using the quadratic equation ax+bx+c=0 with this question I am unsure of what a, b and c are supposed to be, therefore I do not know how to solve this! Please help!
The standard quadratic equation form is
ax^2 + bx + c = 0
and your equation is, if your (2) is supposed to be an exponent,
12x^2 -15x = 0
Therefore a = 12, b = -15 and c = 0
You have reduced your equaion to
4x^2 -5x = 0,
so using a=4, b=-5 and c=0 would give you the same results for x.
You should get x = 0 and x = 5/4 as the solutions, using the quadratic equation
x = [-b +/-sqrt(b^2 -4ac)]/(2a)