Solve (x - 3)(x +1)=12?

Question

Does anyone can show me the steps to solve this quadratic equation using the zero product rule, l got stuck...thank's

Answer 1

expand the brakcets to get

x^2 - 2x - 3 = 12
re-arrange this to make the other side 0
so, subtract 12 from each side
x^2 - 2x - 15 = 0
Facotrise this enw equation back into brackets to get
(x+3) (x-5) = 0
You can then sovle this, getting two answers for x by wriitng each bracket next to 0 and working out what x is
So...
x+3 = 0
this means x = -3
OR
x-5 = 0
this means x = 5

SO
x = 5 OR -3

Answer 2

You need to multiply the left side of the equation and subtract 12 on both sides, so that one side of the equation is zero.

x^2 - 2x - 3 - 12 = 0
x^2 - 2x - 15 = 0

Then you factor the trinomial and apply zero product property.

(x - 5) (x + 3) = 0

x - 5 = 0 or x + 3 = 0

x = 5 or -3

Answer 3

Okay, I think I can help you. First off my answer was 5 and -3.
Let's start with multiplying (x-3) and (x+1)= x2-2x-3
x2 - 2x - 3 = 12

Minus 12 from both sides. x2 - 2x -15 = 0

Factor the equation, (-5 * 3) = -15 and gives us the -2x by minusing -5 and 3.
So we get: (x - 5)(x +3) = 0

And what I do is just take the numbers and reverse their symbol.

Answers are: 5 and 3

Answer 4

5 or -3

Multiply it out using the FOIL method:
x^2 + 1x - 3x -3 = 12
x^2 - 2x - 3 = 12
x^2 - 2x -15 = 0

Then you can use the quadratic equation to plugin 1,-2, and -15.

x = (2 +- sqrt(4+60)) / 2
x = (2 +- sqrt(64)) / 2
x = (2+-8)/2
x = 10/2 or -6/2
x = 5 or -3

Answer 5

If you factor it back out you get
x^2 - 2x -3 = 12

Subtract 12 from both sides and you get
x^2 -2x -15=0

Factor it back out to two numbers that multiply to -15 and add to
-2 and you get
(x-5) (x+3)=0

The Factors of it are 5 and -3

Answer 6

first, solve the parentheses....multiply them..so you'd get x2 (squared)-2x-3=12. then, subtract the 12 on both sides so your equation now looks like x2-2x-15=0. now you can factor it out!! so then it'll look like (x-5)(x+3)=0 and your answer is 5 and -3.

Answer 7

first, multiply it out
x^2 + 2x -3 = 12
move the 12 to the left
x^2 +2x +-15 = 0
use quadradic equation
a=1, b=2, c=-15
it is hard to write in text so go here:
http://mathworld.wolfram.com/QuadraticEquation.html
or here will do it for you by just putting in a,b,c
http://www.1728.com/quadratc.htm

Answer 8

you may desire to get x on one section and numbers onthe different section. 3x + x = a million + 12 4x = 13 now divide 4 to the two facets 4x / 4 = 13 / 4 4s cancel out and leaves x = 3.25 ~~~~~~~~~~

Answer 9

(x-3)(x+1)=12
(x)(x)=x squared
(-3)x =-3x
(1)x = x
x squared +(-3x) + x =
-2x squared

Answer 10

wouldn't you use the foil method?