Answer:
B
Step-by-step explanation:
Since p and v vary inversely then the equation relating them is
p = 
← k is the constant of variation
to find k use the condition p = 8 when v = 40
k = pv = 8 × 40 = 320
⇒ p(v) = 
→ B
Answer:
D
Step-by-step explanation:
<u>Answer:</u>
The equation through (-3, -2) and perpendicular to y = x – 1 is y = -x -5 and option c is correct.
<u>Solution:</u>
Given, line equation is y = x – 1 ⇒ x – y – 1 = 0. And a point is (-3, -2)
We have to find the line equation which is perpendicular to above given line and passing through the given point.
Now, let us find the slope of the given line equation.
We know that, <em>product of slopes of perpendicular lines is -1.
</em>
So, 1 
slope of perpendicular line = -1
slope of perpendicular line = -1
Now let us write point slope form for our required line.
y – (-2) = -1(x – (-3))
y + 2 = -1(x + 3)
y + 2 = -x – 3
x + y + 2 + 3 = 0
x + y + 5 = 0
y = -x -5
Hence the equation through (-3, -2) and perpendicular to y = x – 1 is y = -x -5 and option c is correct.
Answer:
45
Step-by-step explanation:
AEF is a similar triangle to ABC. that means it has the same angles, and the sides (and all other lines in the triangle) are scaled from the ABC length to the AEF length by the same factor f.
now, what is f ?
we know this from the relation of AC to FA.
FA = 12 mm
AC = 12 + 28 = 40 mm
so, going from AC to FA we multiply AC by f so that
AC × f = FA
40 × f = 12
f = 12/40 = 3/10
all other sides, heights, ... if ABC translate to their smaller counterparts in AEF by that multiplication with f (= 3/10).
the area of a triangle is
baseline × height / 2
aABC = 500
and because of the similarity we don't need to calculate the side and height in absolute numbers. we can use the relative sizes by referring to the original dimensions and the scaling factor f.
baseline small = baseline large × f
height small = height large × f
we know that
baseline large × height large / 2 = 500
baseline large × height large = 1000
aAEF = baseline small × height small / 2 =
= baseline large × f × height large × f / 2 =
= baseline large × height large × f² / 2 =
= 1000 × f² / 2 = 500 × f² = 500 ×(3/10)² =
= 500 × 9/100 = 5 × 9 = 45 mm²
Answer:
(2,4)
Step-by-step explanation:
The range is the y values
y = x+5
Let y=7
7 =x+5
Subtract 5
7-5 x+5-5
2=x
Let y= 9
Subtract 5
9-5 x+5-5
4=x
The domain is (2,4)
