A test for checking computations is called casting out nines. Consider the sum 612+301 + 500 = 1473 The remainders when 672, 301, and 500 are divided by 9 are 6, 4, and 5, respectively. The sum of the remainders, 15, has a remainder of 6 when divided by 9, as does 1473 Find the following sum and use casting out nines to check 398+476 + 182 398 476 182

A ship leaves point A and sails north at the constant rate of 12 knots. Two hours later, a second ship leaves A and sails east at the constant rate of 30 knots. How fast are the ships separating when the first ship is 60 nautical miles from A?

Evaluate 3x²Vx³ + 1 dx. -1