Question

How do you solve these?
Please help me, and teach me to do this equation by factoring. Please don't just give direct answer and don't become an introvert.
1) 15x^2 - 7x - 36 = 0
Please explain it to me, I'm new to Factoring.
Thank you :)
Lisa

Answer 1

I think You want to learn how to factorise Quadratic equation.

$a {x}^{2} + bx + c = 0$
step 1 ) you need to break "bx" in such a way that when you add the the term it will be equal to "bx" and when you multiply the term it should be equal to " a×cx^2"

For eg.
${x}^{2} + 3x - 4$
here a = 1 ,b = 3 , c = -4
so you need to break 3x in such a way that it product should eaqual to " a × cx^2" i.e ( 1 × -4x^2)

so , you can write 3x as (-4x +1x) so product will be equal to -4x^2

${x}^{2} - 4x + 1x - 4$
now expression will look like this

you can take x common

$x(x - 4) + 1(x - 4)$
now you can take (x-4) as common
$(x - 4)(x + 1)$

Now 1 more example ,

$6 {x}^{2} + 5x - 6$
now we can write 5x as ( 9x -4x ) so , it's product equal to( ax^2 ×c) i.e (6x^2 ×6 = 36x^2)

$6 {x}^{2} + 9x - 4x - 6$

Always take anything common if you can

$3x(2 {x} + 3) - 2(2x + 3)$

$(3x - 2)(2x + 3)$

Your above Question above could not be factorised by this Method ( or you can say it is hard to factorise by this Method)You have to use Quadratic formula to get the value of X

YOU must be aware of Quadratic Formula..if you are not kindly Search in Google

Factorization can Only be mastered by Practise so... Regularly practise