s-t=3 and s/3 +t/2=6 Solve this simultaneous linear equations by substitution method. [ ICSE Class 9 ML Aggarwal Chapter 5 Exercise 5.1 Question Number 1(ii) Solution]
s-t = 3 —(i)
$\frac{s}{3} + \frac{t}{2}$ = 6—(ii)
From equation (i) we get,
s=t+3 —-(iii)
Substituting the value of s in equation (ii) we get,
$\frac{t + 3}{3} + \frac{t}{2}$ = 6
$\Rightarrow \frac{2(t + 3) + 3t}{6}$ = 6
$\Rightarrow \frac{2t + 6 + 3t}{6}$ = 6
$\Rightarrow 5t + 6$ = 36
$\Rightarrow 5t$ = 36 – 6
$\Rightarrow 5t$ = 30
$\Rightarrow t $= $\frac{30}{5}$
$\Rightarrow t$ = 6
From equation (iii) we get,
s=6+3
⟹ s= 9
Therefore Required Solutions are s = 9 and t=6