Find the value of (115)−2 + (113)−2 + (112)−2.
41
538
0.226
269
Given, (115)−2 + (113)−2 + (112)−2
=(15−1)−2 +(13−1)−2+ (12−1)−2 (∵a−m = 1am)
=(15)(−1 × −2) +(13)(−1 × −2)+ (12)(−1 × −2) (∵(an)m = (a)m×n)
= 152 + 132 +122
=225 + 169 + 144
= 538
Let y=12+13+12+13+..... What is the value of y?