15. 70° because a right angle is 90° and we have the angle of ADB which is 20°. So 90°-20°=70°.
16. 70° because angle PSQ is 60° and angle QSR is 10°. So 60°+10°=70°.
17. 55° because it says it in the explanation. I assume this is a typo and they meant to ask the measurement of ADC and in that case it would be 130° because angle ADB is 75° and angle BDC is 55°. 75°+55°=130°.
18. 40° because angle PSQ is a right angle which means it's 90°. So 130°-90°=40°.
19. 140° because angle ADB is 120° and angle BDC is 20° so 120°+20°=140°.
20. 125° because again it's in the explanation. But if it's a typo and they meant what is the measurement of PSQ then it is 50° because PSR is 125° and QSR is 75° so 125°-75°=50°.
Hope this helps! :)
7:9 because there are 35 children and 10 adults. Add 35 and 10 you get 35:45 then you simplify the ratio to get 7:9.
The value of x is 12 or 32
Substitute the value of b = -2 to the expression
