Linear equation please help

What is the celsius temperature that is equal to 94 degrees fahrenheit using the formula f=9/5 c+32

The sum of two numbers is 12 and their difference is 18 what are the two numbers

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.