Algebraic expressions with exponents

At the beginning of 1974/75,2 years a man invested #2000 in a bank at 12.5% compound interest, if it degree #650 at the end of each two years to pay his son's school fees, after payment of interest to pay his son's school fees, how much did he have left at the beginning of the 1978/79 school year?

(30 points). the population of a city is 45,000 and decreases 2% each year. if the trend continues, what will the population be aer 15 yrs

Find the x-intercepts for the parabola defined by this equation: y=-3x^2-6x+9