During weekdays, Richard is working as a part time library assistant at a university. He needs to work off 30 hours a week. For the first three days of the week, he worked 21 1/5 hours. Complete the working equation that represents the number of hours, h, Richard needs to work to reach 30 hours for the week and solve the equation

1 answer

The working equation that represents the number of hours Richard needs to work to reach 30 hours for the week is:

30 - (21 1/5 + h) = 0

To solve the equation, we can start by simplifying the expression inside the parentheses:

21 1/5 + h = 21 1/5 + (5/5)h = (106/5 + 5h/5) = (106 + 5h)/5

Substituting this back into the equation, we have:

30 - (106 + 5h)/5 = 0

To get rid of the fraction, we can multiply both sides of the equation by 5:

5(30) - 106 - 5h = 0

150 - 106 - 5h = 0

44 - 5h = 0

To isolate h, we can subtract 44 from both sides of the equation:

-5h = -44

Finally, we divide both sides by -5:

h = -44 / -5

Simplifying this division, we get:

h = 8.8

So, Richard needs to work approximately 8.8 hours to reach 30 hours for the week.