The question also states that each brick weighs 4 lb and ask to find 1) the function and 2) the total load if the wheelbarrow carry 20 bricks.
1) Function: weight of the wheelbarrow + weight of the bricks
call x, the number of bricks
f(x) = 42 + 4x
2) total load with 20 bricks
f(20) = 42 + 4(20) = 42 + 80 = 122 lb
