True or false? a function assigns each value of the dependent variable to more than one value of the independent variable

Find the sum of 4x^{2} -4+6 and -7^{2} +3x+1

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?

What is the solution to the equation below? 3/x-2+6=square root x-2 +8