A pendulum travels 30 inches on its first swing. During each of its subsequent swings, it travels 90 percent of the previous swing. ANSWERS
1. 30 and 0.9
2.C, 30(1-0.9^6/ 1-0.9)
3. C, Yes, because |r| < 1.
4. B, 300

the square root of what number? if you add that, then someone will probably answer the question.

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