Answer:
- C) (x − 3)2 = 25
- C) Factor out 4 from 4x2 + 40x.
Step-by-step explanation:
1. Adding the square of half the x-coefficient to both sides of the equation will "complete the square." That square is 9, so the result on the right is 16+9 = 25. Only selection C matches.
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2. To complete the square, you want to be able to put the quadratic into the form a(x -h)^2 = -k. For the purpose, it is most convenient to first factor "a" from the given quadratic. Then you can determine "-h" to be half the x-coefficient inside the parentheses.
Here, that looks like ...
4(x² +10x) = 80 . . . . . . . . . . step 1: factor out 4
4(x² +10x +25) = 180 . . . . . add 25 inside parentheses and the same number (4·25) on the right side of the equation
4(x +5)² = 180 . . . . . . . . . . . written as a square
Answer:
=
−
1
1
Step-by-step explanation:
Using the quadratic equation we get:

Factoring out 2 we get

Factoring out the imaginary number:

So b.
Answer:
55%
Step-by-step explanation:
What we must do is get the total number of people, that is, boys and girls who have been a member for more than 2 years, that is:
children: 0.8 * 35 = 28
girls = 0.25 * 28 = 7
Now, passing knowing the%, would be dividing the sum of the above by the sum of the total club members:
(28 +7) / (35 + 28) = 0.55
Since it is a number below 1, it cannot be a mixed number.