How many solutions does the equation 5x + 3x –4 = 10 have

7friends share 4 pizzas equally how much pizza did each friend get

How do i start to solve? would appreciate a walk-thru! a bird sitting 16ft above the ground in an apple tree dislodges an apple. after how many seconds does the apple land on the ground? (assuming that no branches will interfere with it's fall)

Ineed here’s a picture of the question