<PRE><B>Question 253834</B>
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 = {{{((3R - ac))/a}}}
:
:
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(-3)}}}
x = {{{-1 - sqrt(3)*i}}}
and
x = {{{-1 + sqrt(3)*i}}}</PRE>