ACT Math practice questions and answers
In the complex numbers, where 
, the conjugate of any value a + bi is a– bi.What is the result when you multiply 2 + 7i by its conjugate?
(A) 45
(B) –45
(C) 45i
(D) 53
(E) 53i
The Correct Answer
Pass：Next
Explanation
The ACT Math Test usually breaks down into 6 questions types: pre-algebra, elementary algebra, and intermediate algebra questions; plane geometry and coordinate geometry questions; and some trigonometry questions.