Question

Complete the square to solve 3x^2+12x=9

A. x=3+√6
B. x=2+√7
C. x=-2+√7
D. x=-2+√13

Answer 1

Use the formula
(
b
2
)
2
(
b
2
)
2
in order to create a new term. Solve for
x
x
by using this term to complete the square.
Exact Form:
x
=
±
√
7
−
2
x
=
±
7
-
2
Decimal Form:
x
=
0.64575131
…
,
−
4.64575131
…

Answer 2

Explanation:

3 {x}^{2} + 12x - 9 = 0

`\frac{ - (12) \binom{ + }{ - } \sqrt{ {12}^(2) - 4(3)( - 9)} }{2(3)}`