PLEASE HELP simplify each polynomial.
2x2 + 8 – 4x + 3x – 6x2 + 7
A. –8x2 – 7x + 15
B. –4x2 – x + 15
C. 4x2 + x + 15
D. 8x2 + 7x + 15

If x=-3 is the only x-intercept of the graph of a quadratic equation, which statement best discribes the discriminant of the equation?

Hello can you me find all the products

Awater holding tank measures 105 m long, 50 m wide, and 8 m deep. traces of mercury have been found in the tank, with a concen- tration of 60 mg/l. what is the total mass of mercury in the tank? answer in units of kg.