Asap plz! solve for b. (b+12)^2=81

Sole with work in 10 years, the average number of hours of tv watched per week by teenagers dropped from 23.9 to 21.4. find the percent of change.

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.

Light travels at 186,000 miles per second. light takes about 1 1? 3 seconds to travel from the earth to the moon. calculate the distance between the earth and the moon based on the speed of light.