What number should be added to both sides of the equation to complete the square?

x2 – 10x = 7

The triangles are similar. what is the value of x? show your work.

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)

During a wright loss challenge your friend goes from 125 pounds to 100 pounds.what was the percent weight loss