Question

find the 5th sum with definition

Answer 1

Answer:3n-1 where n=number of square

Step-by-step explanation:

1 square=4 matchstick

2 square=7 matchstick

3 square=10 matchstick

a=4

d=3

An=a+(n-1)d

=4+3n-3

An=3n+1

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