Question

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.​

Answer 1

4X+3Y=17
5X+2Y=16

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

7Y=21
Y=3,X=2

Answer 2

Answer:

pen = 2    book = 3

Step-by-step 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)