Answer:
Jenna spent 7 hours babysitting.
Explanation:
With the information provided, you can say that Jenna's total earnings are equal to the amount she earned cleaning her neighbor's basement plus the result of multiplying the charge per hour for babysitting for the number f hours, which is:
e=20+5x, where:
e represents the total earnings
x is the number of hours
Now, you can replace e with 55 that is the toal amount she earned and solve for x:
55=20+5x
55-20=5x
35=5x
x=35/5
x=7
According to this, the answer is that Jenna spent 7 hours babysitting.