Solve 3x^2=-12-6x by completing the square
1 answer:
Answer:
x = - 1 ± i
Step-by-step explanation:
Given
3x² = - 12 - 6x ( add 6x to both sides )
3x² + 6x = - 12 ( divide through by 3 )
x² + 2x = - 4
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(1)x + 1 = - 4 + 1
(x + 1)² = - 3 ( take the square root of both sides )
x + 1 = ± = ± i
( subtract 1 from both sides )
x = - 1 ± i
You might be interested in
The image of the question is attached below.
Given:
m∠DAC = 20° and m∠BCA = 30°
m∠ABC = 90° and m∠CDA = 90°
To find:
The value of x and y.
Solution:
In right triangle ABC,
m∠BAC = x° + 20°
Sum of the interior angles of a triangle = 180°
m∠BAC +m∠ABC + m∠BCA = 180°
x° + 20° + 90° + 30° = 180°
x° + 140° = 180°
Subtract 140° from both sides.
x° + 140° - 140° = 180° - 140°
x° = 40°
In right triangle ADC,
m∠ACD = y° + 30°
Sum of the interior angles of a triangle = 180°
m∠ACD +m∠CDA + m∠DAC = 180°
y° + 30° + 90° + 20° = 180°
y° + 140° = 180°
Subtract 140° from both sides.
y° + 140° - 140° = 180° - 140°
y° = 40°
The value of x is 40 and y is 40.
