100 POINT AND BRINIEST! DONT ANSWER IF YOU DONT KNOW THAT ANSWER! Describe and correct the error.

Solve: x^3 + 20x = -2x^3 - 7x
3x^3 = 27x = 0
3x( x^2 + 9 ) = 0
3x ( x - 3)(x + 3) = 0
x = { -3, 0, 3}

Find the amount in a continuously compounded account for the given condition. principal: $1000, annual interest rate: 4.8%, time: 2 yr

The lengths of all sides of a triangle are integers when measured in decimeters. one of the sides has length of 1 dm and another of 3 dm. find the perimeter of the triangle.'

Aschool allots ? 1500 to spend on a trip to the theatre. theatre tickets have a regular cost of ? 55 each and are on offer for 1 5 off. a train ticket for the day will cost ? 12 each. if 2 teachers and the maximum number of students attend, how much money will the school have left over?