Answer:
Hey there!
The system can be written as
l+w=20000
w+1000=l
Let me know if this helps :)
Using the information from the question, one can construct two equations:

... (1)

... (2)
by substituting (1) into (2) to find x


\frac{5}{4z} = \frac{1}{4}



⇒ z = 5
By substituting value of z into (1)
⇒ 4 (5) = x
⇒ x = 20
Thus the two numbers are 5 & 20
59.70 for 6 hours of mowing and 1 hour of babysitting !