Answer:
10k ÷ 10 + 1 = k + 1
Step-by-step explanation:
LHS
10k ÷ 10 + 1
10(9) ÷ 10 + 1
90 ÷ 10 + 1
10
RHS
k + 1
9 + 1
10k ÷ 10 + 1 = 10
1 1/2
because each friend gets 1 1/2