X^2 - 4x - 12 = 0 Factor and solve

Ax^2+bx+c=0

find what 2 numbers multiply to get c and add to get b
x^2-4x-12
b=-4
c=-12

x times y=-12
x+y=-4
factor -12
-1, 12
-2,6
-3,4
add
-1+12=11
-2+6=4
-3+4=1

the one that works is -2 and 6 because they can be reversed to make -6 and 2 which multiploy to get -12 and add to get -4 so 

split it up into

x^2-4x-12=(x-6)(x+2)=0
set each to zero
x-6=0
add 6
x=6

x+2=0
subtract 2
x=-2

x=6 or -2

1/8 ÷ 2/5= 5/16

Step-by-step explanation:

1/8 ÷ 2/5 = ?

Dividing two fractions is the same as multiplying the first fraction by the reciprocal (inverse) of the second fraction.

Take the reciprocal of the second fraction by flipping the numerator and denominator and changing the operation to multiplication. Then the equation becomes

1/8 X 5/2 = ?

For fraction multiplication, multiply the numerators and then multiply the denominators to get

1×5

8×2 =5/16

This fraction cannot be reduced.

Therefore:

1/8 ÷ 2/5= 5/16