20 divided by 4 1/2 help, i wil give brainlist if have the step by step

2-digit numbers less than 91 which are 1 less than a multiple of 10

Which statement about the graph of y = 8(0.25)^2

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?