Which algebraic expression is equivalent to the expression below?
10(4x + 3) - 9x a. 31x + 30 b. 31x - 3 c. 40x + 21 d. 49x + 30 i feel the answer is b. but i'm not sure. if someone could type out the equation, that'd be great

Suppose a laboratory has a 30 g sample of polonium-210. the half-life of polonium-210 is about 138 days how many half-lives of polonium-210 occur in 1104 days? how much polonium is in the sample 1104 days later? 9; 0.06 g 8; 0.12 g 8; 2,070 g

Apassenger train and a freight train leave san jose at 3pm, traveling in the same direction. the passenger train is going three times as fast as the freight train. at 6pm they are 240 miles apart. how fast is each travelling? explain your answer and show your

Fran has 7 sheets of paper for a coloring project. if she only uses 1/3of a sheet of paper per draing how many drawings can ahe make?