A) (2x+8)−(x+8)=
B) (7x−2)−(x−9)=

A) x = -16

B) x = 11/6

Step-by-step explanation:

A) (2x + 8) − (x + 8)

= 2x - x + 8 + 8

= x + 16

x = -16

B) (7x − 2) − (x − 9)

= 7x - x - 2 - 9

= 6x - 11

x = 11/6

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

d 600 because 15*10*2=300

300+300=600

step-by-step explanation: