3-5(3a+6) in standard form 7th grade

Match each equation with the operation you can use to solve for the variable. 1 subtract 10 2 divide by 10 3add 18 4add 10 5 subtact 18 6multiply by 5. 7multiply by 10. a 5 = 10p b p + 10 = 18 c p + 18 = 5 d 5p = 10

How do i do this? i don’t understand

7. the area of the playing surface at the olympic stadium in beijing isof a hectare. what area will it occupy on a plan drawn to a scaleof 1: 500?