Remember that multiplication is to be done before addition or subtraction. We see that both terms have the factor 0.85:
0.85 × 0.85 +2 × 0.85 ×0.15 × 0.15 =
0.85 * ( 0.85 + 2*0.15*0.15).
This is equivalent to 0.85 ( 0.85 + 2*0.0225 ) = 0.85 ( 0.895 ).
This last result could be left as is, or evaluated with a calculator:
0.76075
