SOLUTION: 1. Write the a + bi form of (7 - i)^2 (simplify) 2. R = 1/3a(x + c) solve for x 3. x^2 + 2x + 4 = 0

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson  -> Lesson -> SOLUTION: 1. Write the a + bi form of (7 - i)^2 (simplify) 2. R = 1/3a(x + c) solve for x 3. x^2 + 2x + 4 = 0       Log On


   



Question 253834: 1. Write the a + bi form of (7 - i)^2 (simplify)
2. R = 1/3a(x + c) solve for x
3. x^2 + 2x + 4 = 0

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
1. Write the a + bi form of (7 - i)^2 (simplify)
(7 - i)*(7 - i)
FOIL
49 - 7i - 7i + i^2
:
49 - 14i + (-1)
:
49 - 1 - 14i
:
48 - 14i
:
:
2. R = 1/3a(x + c) solve for x
1/3a(x + c) = R
:
Multiply both sides by 3
a(x + c) = 3R
;
Multiply whats inside the brackets by a
ax + ac = 3R
Subtract ac from both sides
ax = 3R - ac
;
Divide both sides by a
x = %28%283R+-+ac%29%29%2Fa
:
:
3. x^2 + 2x + 4 = 0
Solve by completing the square
x^2 + 2x + __ = -4
We can complete the square with
x^2 + 2x + 1 = - 4 + 1
(x + 1)^2 = -3
x + 1 = +/-sqrt%28-3%29
x = -1+-+sqrt%283%29%2Ai
and
x = -1+%2B+sqrt%283%29%2Ai