STATISTICS HELP PLEASE #4

What number should be added to both sides of the equation to complete this square? x^2-10x=7

If the value of x increases by 5, how does the value of m(x + 3) change? a) it increases by 5m. b) it increases by 8m. c) it decreases by 5m. d) it decreases by 8m.

Jane moves from a house with 71 square feet of closet space to an apartment with 45.44 square feet of closet space. what is the percentage decrease of jane’s closet space?