we know 5*3 is 15
and two 15s is 30
so
(5x-3)(5x-3) = 0
so
5x-3 = 0
x = 3/5 twice because both solutions are the same. That means the vertex of the parabola is on the x axis at x = 5
Solve the equation by factoring, show all work.
25x^2-30x+9=0
2 answers
Use AC method of factoring.
25x^2-30x+9 = 0.
A*C = 25*9 = 225 = 3*75 = (-15)*(-15).
Select the set of factors whose sum = -30.
25x^2 + (-15x+(-15x)) + 9 = 0.
(25x^2-15x) + (-15x+9) = 0,
5x(5x-3) + -3(5x-3) = 0,
(5x-3)(5x-3) = 0,
5x-3 = 0, X = 3/5.
25x^2-30x+9 = 0.
A*C = 25*9 = 225 = 3*75 = (-15)*(-15).
Select the set of factors whose sum = -30.
25x^2 + (-15x+(-15x)) + 9 = 0.
(25x^2-15x) + (-15x+9) = 0,
5x(5x-3) + -3(5x-3) = 0,
(5x-3)(5x-3) = 0,
5x-3 = 0, X = 3/5.
1 answer