Simplify the expression below as much as possible. (7-6i) + (-1 + 4i) -(4-7i)
A. 10 + 5i
B. 2 - 9i
C. 10-9i
D. 2 +5i

answer

d. 10

explanation

the distance from point y to wx is the height of the triangle.

using pythagoras theorem,

group similar terms to get,

this implies that,

take positive square root of both sides to get,

this implies that,