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Jonson and Mandy have some story books.
If Jonson gives Mandy 5 books, they will have same number of books.
If Mandy give Jonson 4 books, then the number of Jonson’s books is 3 times as many as Mandy’s.
How many books does Jonson have?
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As you read the text, you write these equations
J - 5 = M + 5 (1) (from the first statement)
J + 4 = 3*(M-4) (2) (from the second statement)
From first equation, express M = (J-5) - 5 = J - 10, and substitute it into the second equation
J + 4 = 3*((J-10)-4).
Simplify and solve for J
J + 4 = 3*(J-14)
J + 4 = 3J - 42
4 + 42 = 3J - J
46 = 2J
J = 46/2 = 23.
ANSWER. Jonson has 23 books.
Solved.