Help I need to know how to do this for extra credit

If the wwight of a package is multiplied by 7/10 the result is 65.8 find the weight of the package

An initial investment of $100 is now valued at $150. the annual interest rate is 5%, compounded continuously. the equation 100e0.05t = 150 represents the situation, where t is the number of years the money has been invested. about how long has the money been invested? use your calculator and round to the nearest whole number. years

Solve each quadratic equation by factoring and using the zero product property. x^2 + 18x = 9x