Distribute 5 to both f and -3
5(f) = 5f
5(-3) = -15
5f - 15 = f + 10
Next, isolate the variables and the constants. subtract f from both sides and add 15 to both sides
5f (-f) - 15 (+15) = f (-f) + 10 (+15)
5f - f = 10 + 15
Simplify
4f = 25
Divide 4 from both sides
4f/4 = 25/4
f = 25/4
f = 25/4, or 6.25 is your answer
hope this helps