Solve the following equations using graphical method: $2a+3b=4$ $a–b+3=0$
Solve the following equations using graphical method: $2a+3b=4$ $a–b+3=0$

Given,

$2a+3b=4$……. (i)

$a–b+3=0$……. (ii)

From equation (i),

⇒ $b=(4–2a)/3$

When $a=-1$, we get $b=(4–2(-1))/3=2$

When $a=2$, we get $b=(4–2(2))/3=0$

Thus, we have the following table giving Points on the line $2a+3b=4$

a $-1$ $2$
b $2$ $0$

From equation (ii),

Solve for b:

⇒ $b=(a+3)$

So, when $a=0$

$b=(0+3)=3$

And, when $a=1$

⇒ $b=(1+3)=4$

Thus, we have the following table giving Points on the line $a–b+3=0$

a $0$ $1$
b $3$ $4$

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

From given graph, the two lines intersect at a single Point P $(-1,2)$

Thus, $a=-1$ and $b=2$.