Solve the following equations using graphical method: 2a+3b+5=0 3a+2b-12=0
Solve the following equations using graphical method: 2a+3b+5=0 3a+2b-12=0

Given,

2a+3b+5=0……. (i)

3a+2b-12=0……. (ii)

From equation (i),

b=-\left( 2a+5 \right)/3

When a=-4, we have b=-\left( 2\left( -4 \right)+5 \right)/3=1

When a=-2, we have b=-\left( 2\left( -2 \right)+5 \right)/3=-1

Thus, we have the following table giving Points on the line 2a+3b+5=0

a          -4     -1

b          1      -1

From equation (ii),

Solve for b:

b=(3a-12)/2

So, when a=4

b=(3(4)-12)/2=0

And, when a=6

b=(3(6)-12)/2=3

Thus, we have the following table giving Points on the line 3a-2b-12=0

a          4      6

b          0      3

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 say P (2,-3)

Hence, a=2 and b=-3.