If the first term is 5 and the common difference is -3?

Scrub a dub toothbrushes are $4.00 each. there is a 10% discount, but there is also a 6% sales tax after the discount is applied. what is the new price after tax? round to the nearest penny

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

Let f(x) = 5/x and g(x)=2x2+5x. what two numbers are not in the domain of f o g