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37 votes
37 votes
Start with some number--->multiply by 4--->add 8--> divide by 3--->theresult is 28. What is the starting numer?

User Nnmware
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1 Answer

29 votes
29 votes

the missing number is 19

Step-by-step explanation:

let the number = y

multiply the number by 4 = 4 × y = 4y

Add 8 to the result above = 4y + 8

Divide by 3 = (4y + 8)/3

The above result is equal to 28


\begin{gathered} (4y +8)/(3)=28 \\ \text{cross multiply:} \\ 3(28)\text{ = 4y + 8} \end{gathered}

84 = 4y + 8

subtract 8 from both sides:

84 - 8 = 4y + 8 - 8

76 = 4y + 0

76 = 4y

Divide both sides by 4:

76/4 = 4y/4

19 = y

the missing number is 19

User Xhinoda
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