What expression is equivalent to -9r + 4r

Aright triangle includes one angle that measures 30º. what is the measure of the third angle? a. 30º b. 90º c. 60º d. 130º

Maria donates a fixed amount, a, to a charity each month. if she donates $300 in 12 months, what is the equation for a? a. a + 300 = 12 b. a × 300 = 12 c. a × 12 = 300 d. a + 12 = 300 e. a + 32 = 100

Ten times the square of a non-zero number is eqaul to ninety times the number