Question

find value of t1,t2,t3

t1 - t2 + t3 = 4

t1 + t2 + 5×t3 = 20

5×t1 + t2 + t3 = 20

solve systematic

Answer 1

firstly add (i) and (ii)
t1+3×t3=12(iv)
then subtract (ii) from (iii)
t3=2×t1
put the value in forth equation
7×t1=12
t1=12/7