2b + 18 = 4b ? whats the answer to b?

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10

Mariano delivers newspaper. he always puts 3/4 of his weekly earnings in his savings account and then divides the rest equally into 3 piggy banks for spending at the snack shop, the arcade and the subway

Aregular hexagonal pyramid has a base area of 45 in2 and a lateral area of 135in 2. what is the surface are are of the regular hexagonal pyramid