Write the result in standard form (1+10i)^2

Question

It is an operation from pre ap calculus

Answer 1

(1+10i)²=(1+10i)(1+10i)

(1+10i)(1+10i)=1+10i+10i+(10i)(10i)

1+20i+(10*10)(i*i)

1+20i+100*i², where i=√-1 and i²=-1

1+20i+100*(-1)

1+20i-100

-99+20i