Question

solve for x: x^2+3x-40=0 ? please solve

Answer 1

hint: -5*8 = -40 and -5+8 = 3

Answer 2

dude please solve i want to learn how to

Answer 3

well what you do is find two numbers that multiply to get -40 and add to get 3 (because -40 is the last term, and 3 is the coefficient on the middle term) once you have those numbers(which I told you are -5 and 8) you do this \((x-5)(x+8)=0\)

Answer 4

this will work if it is factor-able and of the form \(x^2+bx+c=0\)

Answer 5

but i need to solve for x

Answer 6

@walking_stick

Answer 7

x-5=0 implies x=5, x+8=0 implies x=-8

Answer 8

some of this shuold look familiar to you. If you have any questions please ask.

Answer 9

Notcie that (x-5)(x+8)=0. This follows the form ab=0, where (x-5) is a and (x+8) is b. Notice that if ab=0, that means that either a or b must be zero for the equation to be true. Therefore, we set a and b equal to 0 and solve for x.

Answer 10

And then what ?@walking_stick

Answer 11

lol

Answer 12

Well lol thats about it

Answer 13

Just as zzrocker said, if solve x-5=0 and x+8=0 for x and both of these are your solutions, depending on your domain.

Answer 14

Great thanks dudes