Solve the following equations using graphical method: $a–2b=5$ $2a+3b=10$
Solve the following equations using graphical method: $a–2b=5$ $2a+3b=10$

Solution:

Given,

$a–2b=5$……. (i)

$2a+3b=10$……. (ii)

From equation (i) we get,

⇒ $b=(a–5)/2$

When we Put $b=0$, we get, $a=5$

When we Put $a=1$, we get, $b=-2$

Thus, we have the following table giving Points on the line $a–2b=5$

a $5$  $1$
b $0$ $-2$

 

From equation (ii),

Solve for b, we get:

⇒ $b=(10–2a)/3$

So, when we Put $a=5$

We get, $b=(10–2(5))/3=0$

And, when we Put $a=2$

⇒ $b=(10–2(2))/3=2$

Thus, we have the following table giving Points on the line $2a+3b=10$

a $5$ $2$
b $0$ $2$

 

Graph of the equations (i) and (ii) is given below:

From given graph, we can see that the two lines intersect at a single Point $P(5,0)$.

Hence, $a=5$ and $b=0$.