Solve x2 + 12x = –20 by completing the square.
add (startfraction b over 2 endfraction) squared to both sides of the equation. the value of (startfraction b over 2 endfraction) squared in this equation is .
write the left side of the equation as a binomial squared. the left side of the equation becomes ()2.
use the square root property of equality.
isolate the variable: x =

(36) (x+6) (-10 or -2) i got this right on (ed)

Step-by-step explanation:

1 Add  to both sides of the equation. The value of  in this equation is 36.

2 Write the left side of the equation as a binomial squared. The left side of the equation becomes (x +6)2.

3 Use the square root property of equality.

4 Isolate the variable: x = -10 or -2

fist on the left goes with the third on the right. second on the left goes with the fourth on the right. third on the left goes with the second on the right. the fourth on the left goes with first on the right

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional