On one day, 4 chefs and 5 helpers earned $650. On another day working the same number of hours
at the same rate of pay, 5 chefs and 6 helpers
earned $800.

How much does a chef earn each
day?

4c + 5h = 650 and

5c + 6h = 800 where c are chefs, h are helpers

Start by finding an expression for c

4c + 5h = 650
4c = 650 -5h
c = (650- 5h)/4

Then substitute that into the second equation and solve for a number value for h
5 (650-5h)/4 + 6h = 800
(3250-25h)/4 + 6h = 800
Multiply both sides by 4
3250-25h + 24h = 3200
-h = -50
h = 50

Take that 50 and substitute it into the expression we have for c to get a number value for c

C= 650-5(50)/4
C = 650-250/4
C = 400/4
C= 100

Check your first equations, substituting $50 for the helpers and $100 for the chefs.

4 (100) + 5(50) =
400 + 250 = 650

5(100) + 6(50) =
500 + 300 = 800

The correct answer is 10%