What is the value of x in the equation 2x + 9 = 21? (4 points) 2 6 9 15 2. what is the value of z in the equation 5(2z + 4) = 0? (4 points) -2 0 2 20 3. what is the value of c in the equation 2c + 5(c – 5) = 10? (4 points) 0 2 5 10 4. an equation is shown below: 3(4x + 5) = 12 which of the following correctly shows the beginning steps to solve this equation? (4 points) step 1: 12x + 15 = 12 step 2: 12x = –3 step 1: 12x + 5 = 12 step 2: 12x = 7 step 1: 7x + 5 = 12 step 2: 7x = 7 step 1: 7x + 8 = 12 step 2: 7x = 4 5. how many solutions can be found for the equation 3y + 5 – 2y = 11? (4 points) zero one two infinitely many