Since we want it in the form: (x - a)², let's first expand (x - a)² and then equate for the coefficients.
(x - a)² = x² - 2ax + a²
x² + 4x - 15 = x² - 2ax + a²
Now, let's focus on the middle term.
4x = -2ax
4 = -2a
a = -2
Thus, we know that a = -2
Then, we can say (x + 2)² = x² + 4x - 15
x² + 4x + 4 = x² + 4x - 15
Thus, 19 units are needed in order to complete the square to produce:
(x + 2)²
Answer:
the first one
Step-by-step explanation:
<span>Turn the percent to a decimal by moving the decimal point over 2 places to the left. then multiply. so, 1425 * 375</span> = 53.44
Answer:
Stratified sampling
Step-by-step explanation:
Samples may be classified as:
Convenient: Sample drawn from a conveniently available pool.
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
In this question:
Population divided into groups, and random samples are drawn from the groups. This is a mark of stratified sampling.
We have question
<span> /*8 (multiply both sides by 8)</span>
/*6 (multiply both sides by 6)
/-30 both sides
8W=-66-30
8W=-96
W=-12
