Solve x2 + 12x = –20 by completing the square.

x = -10, -2

Step-by-step explanation:

The given equation is

We can rewrite this equation by adding 20 to both sides as

Comparing with , we get

a=1

b = 12

c = 20

Now, add to both sides of the equation.

So add 36 to both sides of the equation

Subtract 20 to both sides

We can rewrite the left hand side of the equation as

Take square root both sides

Thus, the values of x are x = -10, -2

50 min

step-by-step explanation:

they will be decreasing both their times in half

60 / 2 = 30

40/2 = 20

30 + 20 = 50

35-60 students are taking math.