Karani bought 4 pencils and 6 biro pens for sh. 66 and Tachora bought 2 pencils and 5 biro pens for sh. 51

Class: Form 1

Subject: Mathematics

Topic: Linear Equations

Lesson Summary

Karani bought 4 pencils and 6 biro pens for sh. 66 and Tachora bought 2 pencils and 5 biro pens for sh. 51

a) Find the price of each item.
b) Musoma spent sh. 228 to buy the same type of pencils and biro pens. If the number of biro pens he bought were 4 more than the number of pencils, find the number of pencils he bought.



Text Answer


a) Let the cost of biro pen be b
Let the price of a pencil be p
4𝑝+6𝑏=66……..(1)
2𝑝+5𝑏=51………(2)
By elimination method
Multiply (2) by 2 to eliminate p
4𝑝+6𝑏=66
2(2𝑝+5𝑏=51)
4𝑝+6𝑏=66
-4𝑝+10𝑏=102
-4p-4=-36-4
𝑏=𝑠ℎ.9

Substitute b = 9 in (2)
2(𝑝)+5(9)=51
2𝑝+45=51
2𝑝=51−45
2p2=62
p=3

B= sh.9 p = sh.3



b)
B=x + 4
P = x
9(x + 4) + 3x = 228
9x + 36 + 3x = 228
12x = 228 – 36
12x = 192
12x12=19212
X = 16

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