Please please help me plz

Which representation has a constant of variation of -2.5

At the beginning of the year, adrian's savings account balance was \$28$28. each week, he deposits another \$15$15 into that account, and he doesn't spend any of his savings. is his savings account balance proportional to the number of weeks since the start of the year?

Which statement is true about the discontinuities of the function f(x) = x-5/ 3x^2-17x-28