Question 21
Let's complete the square
y = 3x^2 + 6x + 5
y-5 = 3x^2 + 6x
y - 5 = 3(x^2 + 2x)
y - 5 = 3(x^2 + 2x + 1 - 1)
y - 5 = 3(x^2+2x+1) - 3
y - 5 = 3(x+1)^2 - 3
y = 3(x+1)^2 - 3 + 5
y = 3(x+1)^2 + 2
Answer: Choice D
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Question 22
Through trial and error you should find that choice D is the answer
Basically you plug in each of the given answer choices and see which results in a true statement.
For instance, with choice A we have
y < -4(x+1)^2 - 3
-7 < -4(0+1)^2 - 3
-7 < -7
which is false, so we eliminate choice A
Choice D is the answer because
y < -4(x+1)^2 - 3
-9 < -4(-2+1)^2 - 3
-9 < -7
which is true since -9 is to the left of -7 on the number line.
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Question 25
Answer: Choice B
Explanation:
The quantity (x-4)^2 is always positive regardless of what you pick for x. This is because we are squaring the (x-4). Squaring a negative leads to a positive. Eg: (-4)^2 = 16
Adding on a positive to (x-4)^2 makes the result even more positive. Therefore (x-4)^2 + 1 > 0 is true for any real number x.
Visually this means all solutions of y > (x-4)^2 + 1 reside in quadrants 1 and 2, which are above the x axis.
Answer:
1:8
Step-by-step explanation:
75min/10hr
10*60=600
75/600
1/8
Answer:
4100 workers
Step-by-step explanation:
First, recall that
So if 
, then 
.
Second,
We know that 
and 
, which means we should also have 
.
Third,
but as we've already shown, we need to have , so we pick the negative root.
Finally,
Unfortunately, none of the given answers match, so perhaps I've misunderstood one of the given conditions... In any case, this answer should tell you everything you need to know to find the right solution from the given options.
Answer:
82.4 cm
Step-by-step explanation:
The computation of the height is given below:
As we know that each right triangle contains the top angle of 20 degrees
So, the right angle & the bottom corner angle equivalent to
= 180 - 90 - 20
= 70 degrees
Now the height is
tangent = opposite leg ÷ adjacent leg
tan (70°) = height ÷ 30 cm
height = 30 cm × tan (70°)
= 82.4 cm
