Answer:
x = 77/15 or 5 2/15
Step-by-step explanation:
x/7 = 11/15
Multiply each side by 7
x/7 *7 = 11/15 *7
x = 77/15
We can leave as an improper fraction or change to a mixed number
15 goes into 77 5 times with 2 left over
5 2/15
-4y = 8x
Divide both sides by -4
y = -2x
This is in the form of y = kx, where k is the constant of variation.
y = kx is the direct
That means, k = -2.
The constant of variation is B. -2.
Answer:
3h
Step-by-step explanation:
let time be x
total distance = 450
75x+75x=450
150x=450
x=3h
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
============================================
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.
============================================
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.
