Write an equation to represent that 1/3 of the sum of 20 and a number equals 8. what is the number?

x=4

Step-by-step explanation:

1/3 (20 + x) = 8

multiply both sides of equation by reciprocal of 1/3

3/1 * 1/3 (20 + x) = 8 * 3/1

20 + x = 24

subtract 20 from both sides

x = 4

i cant see the graph

step-by-step explanation:

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15