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:
1/3
Step-by-step explanation:
The total number of marbles is
6+12 = 18
P( red) = red/total
= 6/18
=1/3
Answer:
x=1
Step-by-step explanation:
-34x+6=-28
-6 -6
-34x=-34
-34 -34
x=1
Subtract 6 from both sides. on the left the 6 will be canceled out and on the right -28-6= -34
Than you divide -34 on both sides on the left the -34 will be canceled and on the right -34 divided bt-34 is positive 1. So x equals 1.
Answer:
10
Step-by-step explanation:
This means that 12/(2x+1)=8/(x+4). Cross multiply to get 16x + 8 = 12x + 48. Subtract 12x + 8 from both sides to get 4x = 40, so x = 10.
From lea st to greatest it would be 6.200, 6.4, 6.532, and 6.6
