Could someone please help with this asap. Thank you!

Evaluate the expression for the given value of the variable 7a - 4a for a =8

Diane’s bank is offering 5% interest, compounded monthly. if diane invests $10,500 and wants $20,000 when she withdrawals, how long should she keep her money in for? round to the nearest tenth of a year.

Rewrite the following quadratic functions in intercept or factored form. show your work. y = 5x^2 + 10x