500000000000 in scientific notation

Solve the equation for x.3(6x - 1) = 12 i've tried doing the math and i can't find out what i'm doing wrong

Find the 6th term of the expansion of (2p - 3q)11. a. -7,185,024p4q7 c. -7,185p4q7 b. -7,185,024p6q5 d. -7,185p6q5 select the best answer from the choices provided a b c d

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25