Answer:
y = 
Step-by-step explanation:
Given that y varies directly as x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 7 when x = 3
k = 
= 
, thus
y = x ← equation of variation
When x = 7, then
y = × 7 =
Answer:
Part A:
The surface area of a cylinder is given by
A= 6πr² if h= 2r
Part B:
Total Cost of covering the cylinder = Rate *2πrh + rate*2πr²
Cost of covering only the side = Rate *2πrh
Step-by-step explanation:
Part A:
The surface area of a cylinder is given by
A= 2πrh + 2πr²
Where h= height and radius = r
But we have the height twice as radius so h= 2r
So putting h= 2r we get
A= 2πr(2r) + 2πr²
A= 4πr² + 2πr²= 2πr²(2+1) = 2πr²(3)= 6πr²
Part B:
Cost = Rate * area of the wall + rate * area of the top and bottom
Cost = Rate *2πrh + rate*2πr²
Where area of the top and bottom= πr² +πr² =2 πr²
and area of the side = 2πrh
Multiplying both with the rate and then adding would give the total cost of materials needed to cover the outside of the cylinder and from top and bottom as well.
If you do not need to cover top and bottom then the expression would be
Cost of covering only the side = Rate *2πrh
Part C:
Already done above.
In standard form, slope is always the negative of the x coefficient over the y coefficient.
If you dont want to have that memorized, you can use algebra to get the equation of the line into slope-intercept form (y=mx+b)
Set it equal to y
2x - 5y = 6
2x = 5y + 6
2x - 6 = 5y
(2/5)x - 6/5 = y
Now it is in slope intercept form. In slope intercept form, the coefficient multiplying with x is the slope of the line. Therefore, the slope equals 2/5.
Answer:
1. x = 21
2. m∡ABC = 51°
Step-by-step explanation:
First problem, solve for x
the sum of inside angles of a triangle is 180
also the supplementary angle for L = 180 - 100 is 80°
now you can add all angles
80 + 2x - 11 + 2x + 27 = 180
4x + 96 = 180
4x = 84
x = 21
Second problem, solve for m∡ABC
the sum of inside angles of a triangle is 180
also the supplementary angle for C = 180 - 148 is 32°
now you can add all angles
31 + 2x - 15 + x - 5 = 180
3x + 12 = 180
3x = 168
x= 56,
now solve for m∡ABC = (x - 5)° = (56 - 5)° = 51°
Answer:
<h2>90 min or 1hr 30 mins</h2>
Step-by-step explanation:
Even though the options to choose from are not given in this question we can try and lay our hand on the most likely equation for the number of minutes Jack reads his book.
firstly on a daily Jack reads a total of = 8+10 = 18 mins
He attends school from Mon- fri = 5 days
Now on a weekly basis jack reads = 5*18
in other words, the equation is simply the number of days times the time spent to read his book per day
hence this is = 90 min or 1hr 30 mins
