(2x–y)²–(y+2)²-----------
1 answer:
Answer:
4x² -4xy -4y -4
Step-by-step explanation:
In this case, a= 2x -y and b= y +2.
(2x -y)² -(y +2)²
= (2x -y +y +2)[2x -y -(y +2)]
= (2x +2)(2x -y -y -2)
= (2x +2)(2x -2y -2)
= 2x(2x) +2x(-2y) +2x(-2) +2(2x) +2(-2y) +2(-2) <em>(expand)</em>
= 4x² -4xy -4x +4x -4y -4
= 4x² -4xy -4y -4
Alternatively, start by expanding the brackets.
(2x -y)² -(y +2)²
= 4x² -4xy +y² -(y² +4y +4)
= 4x² -4xy +y² -y² -4y -4 <em>(</em><em>expand</em><em>)</em>
= 4x² -4xy -4y -4 <em>(</em><em>simplify</em><em>)</em>
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Answer:
6) 6
9) 40
10)
11) 13
Step-by-step explanation:
6)A right triangle rule: if 2 legs are equal, the hypotenuse is the length of that leg*
9) Pythagorean Theorem
We know the hypotenuse (41) so we substitute that for c and 9 for b now we need to find a
which gives us 40
10) same with #6 but we do the opposite. SInce we have the hypotenuse, we can divide that by because we know that if 2 legs are equal, the hypotenuse is multiplied by
. Multiply the numerator and denominator by
because we can't have a square root in the denominator.
11) like #9 we have the a and b but we need to find c
a=5 b=12 c=r
so which gives us 13
Answer:
a) Domain =
b)
c) 53.03 worker hours
d) 83.33 worker hours
e) 83.33 worker hours
Step-by-step explanation:
We are given the following in the question:
where W(x) is the number of worker-hours required to distribute new telephone books to x% of the households in a certain rural community.
a) Domain of function.
The domain is the all the possible values of x that the function can take.
Domain =
b) Values of x
Since x is a percentage in reference to context, it can only take value upto 100. Also it cannot take any negative value.
So domain n reference to context will be
c) worker-hours were required to distribute new telephone books to the first 70% of the households
53.03 worker hours were required to distribute new telephone books to the first 70% of the households.
d) Worker hour for entire community
For entire community, x = 100
83.33 worker hours were required to distribute new telephone books to the entire households.
e) Percentage of the households in the community for 3 worker hours
Thus, 4.74% of the households in the community had received new telephone books by the time 3 worker-hours had been expended.