i need help with x and y input output tables for 7th grade i don't understand what 5x means or what to do!

Math hw problems:
1. y=4x+3 x=1,2,5,10,20
2.d=3.5t t=1,2,5,10,20
Please help ASAP!!!!!

2 answers

whatis y=4x+3
to figure out what x is you have to get the numbers to cancel out so that the vairiable will stand alone