1. Grade 10 Academic (MPM2D) Unit 1: Linear System Word Problems with Linear Systems 1
Mr. Choi
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2. Word Problems with Linear Systems Many problems that involve two unknown quantities can be solved using a system of linear equations. We learned how to setup the linear systems in the previous lessons; it is now your choice to select the appropriate method to solve the systems to find the solutions.
Word Problems with Linear Systems 1
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3. Let x and y represent the numbers.
Example 1: Number Problems: The sum of two numbers is 49. Their difference is 11. Determine the numbers.
Let x and y represent the numbers.
Add:
The numbers are 30 and 19.
Word Problems with Linear Systems 1
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4. Let x and y represent the dimensions in metres.
Example 2: Geometry Problems: A rectangle with a perimeter of 40 m is 2 m longer than it is wide. Determine the dimensions of the rectangle.
Let x and y represent the dimensions in metres.
Recall: P = 2(L + W) y 9m x
Add:
11m
The dimensions are 11 m by 9 m.
Word Problems with Linear Systems 1
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5. Let x represent the number of $20 bills
Example 3: Money Problems: Bob has a total of $425 all in $20 bills and $5 bills. He has a total of 31 bills. How many $20 bills does he have?
Let x represent the number of $20 bills
Let y represent the number of $5 bills
Subtract:
Bob has 18 twenty dollar bills
… and 13 five dollar bills
Word Problems with Linear Systems 1
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6. Example 4: Age problems. Sue is six years older than Joe
Example 4: Age problems. Sue is six years older than Joe. Four years ago she was twice as old as Joe was. How old is Joe now?
Let x represent Sue’s current age
Let y represent Joe’s current age
Age
Now
4 years ago
Sue x
Joe y
From (1)
Joe is 10 years old now
and Sue is 16 years old now
Word Problems with Linear Systems 1
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7. Homework
Work sheet: Word Problems with Linear Systems (All) Text: Check the website for updates
Word Problems with Linear Systems 1
© 2017 E. Choi – MPM2D - All Rights Reserved

8. End of lesson Word Problems with Linear Systems 1
© 2017 E. Choi – MPM2D - All Rights Reserved