Find the unique four-digit integer n with these properties:

the last digit (the units digit) of n is 9.

the digits of n add up to 27.

two digits of n are the same.

n is a perfect square

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?

Evaluate the expression for the given value of the variable 7a - 4a for a =8

Agroup of students want to create a garden. they do not know the exact measurements but they propose using a variable to represent the length and width of the garden. the length of the garden is 10 feet longer than double the width. use a single variable to write algebraic expressions for both the length and width of the garden. write an algebraic expression for the area of the garden. use mathematical terms to describe this expression.