Aim #17: How do we solve word problems using linear equations? (day 2)
HW: Handout
Do Now: 1) John is 10 and Billy is 2. John is presently how many times Billy's age?
2) Two years later, John is 12 and Billy is 4. John will now be how many times
Billy's age?
3) Joe has 4 coins in his pocket. How much money does he have?
4) Dave has $2.40 in coins in his pocket. How many quarters, dimes and nickels
does he have?
For the following word problems, only a complete algebraic solution will be
accepted.
1) John is now 3 times as old as his brother Sam. In 5 years, John will be twice as
old as Sam will be then. Find their present ages.
2) Marion is twice as old as Judy. Six years ago, Marion was three times as old as
Judy was then. Find their present ages.
3) Phil is 24 years older than Stan. Four years ago, he was 7 times as old as Stan
was then. Find their present ages.
4) The sum of a man's age and his daughters age is 50 years. Eight years from now,
the man will be twice as old as his daughter will be then. Find their present ages.
5) Derek is three times as old as Brandon. Eight years from now, Derek's age will
exceed twice Brandon's age at that time by 14 years. Find their present ages.
6) Bill has 4 times as many quarters as dimes. In all he has $2.20. How many coins
of each type does he have?
7) Howard has $2.05 in quarters and dimes. He has 4 more quarters than dimes.
Find the number of each coin he has.
8) A purse containing $3.20 in quarters and dimes has, in all, 20 coins. Find the
number of each kind of coin.
9) Harry deposited $4.50 in nickels, quarters and dimes into his piggy bank. The
number of dimes exceeded the number of nickels by 5, and the number of
quarters was 16 less than the number of nickels. Find the number of each coin he
deposited.
10) A class contributed $19.00 in quarters and dimes to a local shelter. In all there
were 100 coins. How many of each kind were there?
Sum it up
If you‛re wondering what the variable (or unknown) should be when working on a
word problem, look at what the problem is asking. This is usually what your
variable is!