What is x please help

Which of the following is true for the relation f(x)=2x^2+1

Acompany charges $0.10 for each letter engraved. bobby plans to spend no more than $5.00 on the engraving on a jewelry box. write and solve an inequality to find the maximum number of letters he can have engraved.

5. (04.07)which of the following exponential functions goes through the points (1, 12) and (2, 36)? (2 points)f(x) = 3(4)^xf(x) = 4(3)^-xf(x) = 3(4)^-xf(x) = 4(3)^x