19. It notes or hints to using the quadratic formula because the equation can not be solved by factoring alone. Thus you must use the quadratic formula. A=-16 B=25 C=3 It is so hard to type a normal equation let alone one of the quadratic formula so I will just attach a picture instead. However you will end up getting two roots/zeros/x-intercepts of -0.11 and 1.67. However since it is an application question asking for answers only in the first quadrant you must choose the positive x-intercept. Therefore the water balloon will land at 1.67 seconds.
20. This question is very simple as it asks you to find a height at a given time. You simply put the given time (1second) into the equation and get your answer. h=-16(1)^2+25(1)+3 h=12
Take it apart mentally cylinder+2hemispheres 2hemispheres=2half spheres=1 sphere 15=radius of sphere+legnth of cylinder+radius of spehre diameter=5 d/2=5/2=r 15=2.5+legnth+2.5 10=legnth of cylinder surface area of sphere=4pir^2 surface area of cylinder (not including bases) is pidh sphere radius=2.5 SA=4pi2.5^2 SA=4pi6.25 SA=25pi SA=78.5 sphere area SA=5pi10 SA=50pi SA=157 add them 78.5+157=235.5 mm^2