multiply the ones in bracket by the L
T = 7× L + L × RS
T = 7L + LRS
making S the subject by transferring 7L to the left hand side of the equation.
thus
T - 7L = LRS
dividing through by LR
[tex] \frac{T}{LR} - \frac{7L}{LR} = S[/tex]
[tex] S= \frac{T}{LR} - \frac{7}{R} [/tex]
