SOLUTION: For i =square root −1, if 3i(2 + 5i) = x + 6i,then x = ? A. –15 B. 5 C. 5i D. 15i E. 27i

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson -> SOLUTION: For i =square root −1, if 3i(2 + 5i) = x + 6i,then x = ? A. –15 B. 5 C. 5i D. 15i E. 27i      Log On


   

Question 595213: For i =square root −1, if 3i(2 + 5i) = x + 6i,then x = ?
A. –15
B. 5
C. 5i
D. 15i
E. 27i
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
3i(2 + 5i) = x + 6i


6i + 15i^2 = x + 6i


6i + 15(-1) = x + 6i


6i - 15 = x + 6i


- 15 = x


x = -15


So the answer is choice A