Z varies jointly as the values of P and T. If I = 1200 when P = 5000 and T = 3, find I when P = 7500 and T = 4

For each proportion find the unknown number x 1/5/8=×/15

2x minus y equals 6, x plus y equals negative 3

Answer asap! show all work! find the number of complex roots, the possible number of real roots and the possible rational roots of the polynomial function. then, solve for all roots. x^3 + 2x^2 + 3x + 6 = 0