Given,
$3a–5b=20$……. (i)
$6a–10b=–40$……. (ii)
From equation (i),
⇒ $b=(3a–20)/5$
When $a=5$, we have $b=(3(5)–20)/5=-1$
When $a=0$, we have $b=(3(0)–20)/5=-4$
Thus, we have the following table giving points on the line $3a–5b=20$.
| a | $5$ | $0$ |
| b | $-1$ | $-4$ |
From equation (ii),
Solve for b:
⇒ $b=(6a+40)/10$
So, when $a=0$
$b=(6(0)+40)/10=4$
And, when $a=-5$
⇒ $b=(6(-5)+40)/10=1$
Thus, we have the following table giving points on the line $6a–10b=–40$
| a | $0$ | $-5$ |
| b | $4$ | $1$ |
Graph of the equations (i) and (ii) is given below:
From graph it is clear that, there is no common point between these two lines. Hence, the given systems of equations is in-consistent.