A vendor sells a exercise book and 3 rulers for 190. Another vendor sells a expense book and 5 rulers for 250. Find the cost of one ruler using the elimination method.

Tutaweka $x$ kuwa gharama ya kitabu kimoja cha mazoezi na $y$ kuwa gharama ya rula moja.
Kutoka taarifa ya kwanza:

$$x + 3y = 190 \quad \text{(Mlinganyo 1)}$$

Kutoka taarifa ya pili:

$$x + 5y = 250 \quad \text{(Mlinganyo 2)}$$

Ili kuondoa $x$, tutatoa Mlinganyo 1 kutoka Mlinganyo 2.

$$(x + 5y) - (x + 3y) = 250 - 190$$ $$x + 5y - x - 3y = 60$$ $$2y = 60$$

Gawanya pande zote mbili kwa 2 ili kupata thamani ya $y$.

$$\frac{2y}{2} = \frac{60}{2}$$ $$y = 30$$

Gharama ya rula moja ni shilingi 30.

Gharama ya rula moja ni:

$$\text{Sh. } 30$$