Algebra one please help

True or false: the graph of y=f(bx) is a horizontal compression of the graph y=f(x) if b< 1

What rule describes a dilation with a scale factor of 4 and the center of dilation at the origin?

Darcy deposited $390 into a savings account. as long as the account balance remains at or above $150, she does not have to pay a service fee for the account. for how many months can she withdraw $40 a month without having to pay service fees? a) 3 b) 5 c) 6 d) 9