Find the sum of the G.p.2+6+18+54+...+1458

Answer 1

a = 2
r = 3
2*729 = 1458
729 = 3^6, so

S7 = 2(3^7-1)/(3-1) = 2*2186/2 = 2186

Answer 2

Solve the equation simultaneously.1/3x+y=3,x+1/2y=4