Answer:
<em>x = 1 + ( √ 10 )/ 2, or x = 1 - ( √ 10 )/ 2; Option A</em>
Step-by-step explanation:
See steps below;
I would prefer answering this question by completing the square, rather than applying a quadratic formula;
3x^2 - 6x - 12 = 0, ⇒ Add 12 to either side,
3x^2 - 6x = 12, ⇒ Divide either side by 3,
x^2 - 2x = 4, ⇒ Write the equation in the form x^2 + 2ax + a^2 = (x + a)^2,
x^2 - 2ax + a^2 = 4 + a^2, ⇒ Solve for a
2ax = -2x,
a = - 1, ⇒ Substitute value of a,
x^2 - 2x + 1 = 4 + 1,
( x - 1 )^2 = 5, ⇒ Solve for x,
x = √5 + 1, and x = - √5 + 1,
In other words; <em>Solution : x = 1 + ( √ 10 )/ 2, or x = 1 - ( √ 10 )/ 2; Option A</em>
She made the mistake of grouping unlike terms and factorizing.
Given that
Helene is finding the sum (9 + 10i) + (–8 + 11i).
She rewrites the sum as (–8 + 11)i + (9 + 10)i.
We have to determine
Which statement explains the property of addition that she made an error in using?
According to the question
The mistake she did is in the second term distributing.
(9+10i) is not equal to (9+10)i
Similarly (-8+11i) is not equal to (-8+11)i.
The correct method she should have done is given below;
Grouping real terms together and imaginary terms together and finding the sum is,

Hence, she made the mistake of grouping unlike terms and factorizing.
To know more about Complex Number click the link given below.
brainly.com/question/10078818
Answer:
y=6
Step-by-step explanation:
Differentiate the equation
dy/dx=2x-8
Find the value of x in equation form
2x-8=0
x=8/2=4
Now x=4 is the line of symmetry or the parabola of the quadratic equation.
Plug back x=4 into the equation to find the turning point(minimum value)
y=(4)²-8(4)+22
y=16-32+22
y=6
Close.. it's actually 540 in² Area is always given in square units of measure
The answer is D..............