Question

please help i got to help my little sister with her math and i have no idea how o do this!!

solve the quadratic equation
(2x-2)(x+7)=0

Answer 1

ok, so since when they are multiplied they equal zero, then either one of them is zero or they both are zero. that yeilds
\[2x-2 = 0\] and\[x+7 = 0\] let me know if you need help with those equations.

Answer 2

Note: you will have two different answers

Answer 3

how do they equal 0?

Answer 4

it's like this:\[a * b = 0\] either a or b can be equal to zero, since anything times 0 is equal to 0

Answer 5

in this case a is 2x-2 and b is x + 7

Answer 6

so wouldnt 2x-2= 0x and x+7= 7x?

Answer 7

and that would give you 0X . 7x and that give is 0 right?

Answer 8

you can't have 0x, because anything times 0 is 0.

there will be two answers, since two values of x can make the expression equal to 0. If x=1, then (2x-2)(x+7) = (0)(8) = 0, so 1 is one of the answers. If x = -7, then (2x-2)(x+7) = (-19)(0) = 0, so -7 is another answer.

The way you find both answers is you set each term equal to 0 like i did before.
2x-2 =0 and x+7=0.

Answer 9

okay i am sorry but i dont understand any of that