You took a math test with 20 questions on it. Your teacher said you got 90% of the problems correct. How many questions did you get correct on the test?
a.
9
b.
15
C.
18
d.
90

Please hurry

Hello as fast as i can answer 18.

Step-by-step explanation:

Reason 20 times 5 equals a 100

so 18 times 5 equals 90.

there for 18 is your answer.

-

Have a good day.

C. 18

Step-by-step explanation:

90% of 20 is 18! Good luck!

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