18. Find the equation for a line Which passes through points 9) and 3). Write equation in slope-intercept form. Show work. 19. Find the exact solutions and simplify as much as possible: 5x2 6x + 3. Show work. 20. I-etf(x) 3.r2 + 9 and g(x) = x 2. (a) Find the composite function(f o simplify. Show Work. (b) Find (f o Show work. 21. A projectik is launclkd from a platform 6 feet high with an initial velocity of 80 feet The Irighth of the projectile att seconds after launch is given by h + 80t + 6 feet. (a) HOW many seconds after launch does the projectile attain maximum height? Show work. (b) What is the maximum height? Show w ork. 22. Solve: 28 . Show work. 23. Suppose that COS = 12/13 and that 9 is a Quadrant IV angle. (a) Find the exact value Of sin Show work. (b) Find tlr exact value of sin(2B). Show work. 24. Prove the I (cos x sin x)2 sin 2x