Sam left his school at 3: 05. he walked at a speed of 3.2 mph. 15 minutes later, al started running after him, and he caught up with sam 10 minutes later. what was al’s speed?

8 mph

explanation:  

Time Sam left his school = 3:05  ( 1/4 hr )

Walked at a speed of 3.2 mph

Al’s speed?

AI caught up with Sam 10 minutes later

Time AI ran for = 1/6 hr

Speed = distance /time

Sam’s distance  

3.2 x 1/4 = 0.8 miles

Simultaneous in the same 10 minutes, Sam walks 3.2 x 1/6 =0.53 miles.

AI ran the total distance of -> 0.8+ 0.53 = 1.3 miles  

Speed = distance /time

1/3 divided by 1/6 = 4/3  

4/3 * 6 = 24/3 = 8 mph

drop out of school or go to quizlet, quizlet is better

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