Answer:
The type of sampling method Dr. Lawrence going to use is Quota Sampling.
Step-by-step explanation:
In quota sampling participants are chosen nonrandomly so it is not a representative sampling method. In this case Dr.Lawrence has a quota of 15% for first-time students and 85% for returning, so the survey she is conducting is non-random. The sampling method she should use is Quota Sampling.
Answer:
d. 12xy
Step-by-step explanation:
The + signs separate terms.
Answer: 
Step-by-step explanation:
Given
The perimeter of one equilateral triangle is P
The lengths of the equilateral triangle are equal
Suppose x is the length of each side
i.e.
<em>Greetings from Brasil...</em>
According to the statement of the question, we can assemble the following system of equation:
X · Y = - 2 i
X + Y = 7 ii
isolating X from i and replacing in ii:
X · Y = - 2
X = - 2/Y
X + Y = 7
(- 2/Y) + Y = 7 <em>multiplying everything by Y</em>
(- 2Y/Y) + Y·Y = 7·Y
- 2 + Y² = 7X <em> rearranging everything</em>
Y² - 7X - 2 = 0 <em>2nd degree equation</em>
Δ = b² - 4·a·c
Δ = (- 7)² - 4·1·(- 2)
Δ = 49 + 8
Δ = 57
X = (- b ± √Δ)/2a
X' = (- (- 7) ± √57)/2·1
X' = (7 + √57)/2
X' = (7 - √57)/2
So, the numbers are:
<h2>
(7 + √57)/2</h2>
and
<h2>
(7 - √57)/2</h2>
16/80 = 1/5 just put it into the calculator
