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4. Ann bought four pens and three exercise books for a total of sh 17 while peter bought five

similar pens and two exercise books for a total of sh.16 find the cost of a pen and an exercise
book.​

2 Answers

3 votes

Answer:

pen = 2 book = 3

Explanation:

p= pens

b=books

4p +3b =17

5p+2b=16

Multiply the first by 5

Multiply the second by -4

Add both (p variable will ce cancelled)

20p +15b = 85

-20p -8b = -64

7b = 21

b=3 (book =3)

Lets plug this in one of the equations

4p + 3x3 = 17

4p +9 0 19

4p = 8

p= 2 (pencil = 2)

User Zkunov
by
5.7k points
4 votes
4X+3Y=17
5X+2Y=16

Times 5=20X+15Y=85
Times 4=20X+8Y=64

7Y=21
Y=3,X=2
User Andrew Jens
by
7.1k points