I need help pls this is to hard for me

If 1/2+2/5s=s-3/4,what is the value of s? a. s=3/4 b. s=25/12 c. s=-25/12 d. s=-3/4

Solve with work both bert and ernie received an increase in their weekly salaries. bert's salary increased from $520 to $520. ernie's salary went from $580 to $645. find the percent of increase for each salary. what was the larger of the two percents ?

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)