Is 8 a solution to 3x + 9 = 13?

No

Step-by-step explanation:

3x + 9 = 13

Subtract 9 from each side

3x + 9-9 = 13-9

3x = 4

Divide each side by 3

3x/3 = 4/3

x = 4/3

8 is not a solution

boxplot e is the answer

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