Perform the addition or subtraction and write the result in standard form.
$$- ( 7.2 - 12.3 i ) - ( 8.1 - \sqrt { - 1.21 } )$$
A) $- 15.3 + 13.4 i$
B) $0.9 + 13.4 i$
C) $- 0.9 + 11.2 i$
D) $- 15.3 + 11.2 i$
E) $15.3 + 13.4 i$

Question

Quizplus · Accepted Answer

First, simplify the square root: $\sqrt{-1.21} = \sqrt{1.21}i = 1.1i$. Then, perform the subtraction: $- (7.2 - 12.3i) - (8.1 - 1.1i) = -7.2 + 12.3i - 8.1 + 1.1i = -15.3 + 13.4i$.

Perform the Addition or Subtraction and Write the Result in Standard