Let X = the number of yards he needs to mow.
Each yard he gets $25, so you would multiply 25 by x to find the total amount he makes.
Now you have 25x.
He needs at least $400 total.
At least means the amount can either equal 400 or be greater than 400.
This would make the inequality:
25X ≥ 400
Now to solve, divide both sides by 25:
25x ≥ 400 =
x ≥ 400 / 25
x ≥ 16
He needs to mow at least 16 yards.
