Simplify the following expression into the form a + bi, where a and b are rational numbers. (4-i)(-3+7i)-7i(8+2i), please help

Steve wants to develop a way to find the total cost of any item including sales tax. the sales tax in his city is 6%. his friend jenna writes the expression x + 6x where x is the cost of the item. explain whether her expression is correct based on the situation.

The surface area of the triangular prism is .

Your friend uses c=50p to find the total cost, c, for the people, p, entering a local amusement park is the cost of admission proportional to the amount of people entering the amusement park? explain.