Factor the quadratic expression completely.
-7x^2-24x-9=

Bob the builder is making 480kg of cement mix. this is made by cement, sand and gravel in the ratio 1: 3: 4

Solve the equation: x - 9 = -6 + 5 a. 21 b. 7 c. 14 d. 2

Aliter of water contains about 3.35 x 10^25 molecules. a certain river discharges about 2.9x 10^8 l of water every second. about how many molecules does the river discharge every minute? write your answer in scientific notation