y is the total pay
x is the hours worked
a is the rate per hour
y = ax
Let's find "a", the rate per hour
He worked 22 hours and made $169. Substitute those numbers in our equation y=ax.
169 = a*22
169/22 = a
7.68181818182 which is approx $7.68
so our equation is y=7.68x
If he works 40 hours:
y=7.68x
y = 7.68 *40
y = 307.20
So 40 hours of work = $307.20