Its the last one because you plug in the 20(x) for example y=20x
and your table looks like this
x 0/2/4
y 0/40/80 y x
because 20(2)=40 then you would do the same with the rest of the equation
20(4)= 80 there fore the last on is your answer
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.
<span>Point slope form is (y - y1) = m(x - x1), where m is a slope of 2, and x1 = 0 and y1 = 0 are our point at the origin. Therefore, we can plug in these values to get the point slope equation for our line:
(y – 0) = 2*(x - 0)</span>
5 3/4 divided by 4 1/2 23/4 divided by 9/2 23/4 times 2/9 46/36 = 1 and 10/36 (reduced) = 1 and 5/18 inches
