Unit 6 Lesson 5: Exercise 2

2.  The line with equation y + ax = c, passes through the points (1, 5) and (3, 1).
Find a and c. (Hint: For the point (1, 5), put x = 1 and y = 5 into y + ax = c.
For the point (3, 1), put x = 3 and y = 1 into y + ax = c.)

3.  The line y = mx + c passes through (2, 5) and (4, 13). Find m and c.

4.  A grandfather is ten times older than his granddaughter. He is also 54 years older than her. How old is each of them?

5.  A two digit number is such that the sum of its digits is 11. The number is 27 greater than the number obtained by interchanging the digits. Find the number.

6)  7 cups and 8 plates cost $6.30. Eight cups and 7 plates cost $6.45. Calculate the cost of a cup and a plate.

7)  A man’s age and his son’s age add up to 45 years. Five years ago the man was 6 times as old as his son. How old was the man when his son was born?

8)  Pat’s age and David’s age add up to 29. 7 years ago, Pat was twice as old as David. Find their present ages.

9)  Four knives and six forks cost $1.36. Six knives and five forks cost $1.64. Find the cost of a knife and a fork.

10)  A trader can buy either two televisions and three video-recorders for $1750 or four televisions and one video–recorder for $1250. Find the cost of one of each.