Help please I’ll give you as much as points as I can

Cherie works in retail and her weekly salary includes commission for the amount she sells. the equation s=400+0.15c models the relation between her weekly salary, s, in dollars and the amount of her sales, c, in dollars. interpret the slope of the equation.

Abank manager wants to encourage new customers to open accounts with principals of at least $2 comma 500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?

In isosceles right triangle $abc$, point $d$ is on hypotenuse $\overline{bc}$ such that $\overline{ad}$ is an altitude of $\triangle abc$ and $dc = 5$. what is the area of triangle $abc$?