What is the missing length

The lines shown below are parallel. if the green line has a slope of -1, what is the slope of the red line?

Onnie is considering doing some long term investing with money that she inherited. she would like to have $50,000 at the end of 30 years. approximately how much money would lonnie need to put into an account earning 6% interest compounded annually in order to meet her goal?

Interpret the following expression (5y^2-7)^3/(2y)^2