Answer:
See Below
Step-by-step explanation:
The surface area of cylinder is given by the formula:

Where
r is radius ( diameter is 4, so radius is 4/2 = 2)
h is height ( h = 9)
Lets find original surface are:

<u>Halving diameter:</u>
diameter would be 4/2 = 2, so radius would be 2/2 = 1
So, SA would be:

<u>Halving height:</u>
Height is 9, halving would make it 9/2 = 4.5
Now, calculating new SA:

Original SA is
,
Halving diameter makes it 
Halving height makes it 
So, halving diameter does not have same effect as halving height.
y-3=3(x+1)
opening the bracket
y-3=3x+3
y=3x+3+3
equation of the line in the form y=mx+c;
y=3x+6
therefore gradient=3
parallel lines have same gradient therefore gradient of the other line is 3
y--3/x-0=3
y+3=3(x-0)
y+3=3x-0
y=3x-3.
Answer:
Step-by-step explanation:
you divide the two to the y, which is x=3/2y
then, you simplify the second equation to y, which is -3y= -4x+12
then, you substitute the x=3/2y into the second equation,
-3y = -6+12
-3y = 6
y = -2
Substitute the y into the first equation, x= 3/2y,
x = -3
Answer:
m = -2
Step-by-step explanation:
First, let's move all variables to one side of the equation. (Don't forget to change the signs when you move the numbers to the other side.)
18m + 7m = -60 + 2 + 8
Now we simplify to get this:
25m = -50
Now we divide -50 by 25 which gets us -2.
Therefore, m = -2
Hope this helps!
The number of dimes is 75 coins.
The number of nickels is 1 coin.
<u>Step-by-step explanation:</u>
It is given that,
A box contains 76 coins, only dimes and nickels.
- The 10 cent coin is called a dime.
- Let, the number of dimes be x.
- The 5 cent coin is called a nickel.
- Let, the number of nickels be y.
<u>This is represented by the system of equations :</u>
x + y = 76 -------(1)
10x + 5y = 4.90 ------(2)
Multiply eq (1) by 5 and subtract eq (2) from eq (1),
5x + 5y = 380
-<u>(10x + 5y = 4.90)</u>
<u>-5x = 375.1</u>
x = 375/5
x = 75 coins.
The number of dimes is 75 coins.
Substitute x=75 in eq (1),
y = 76 - 75
y = 1 coin.
The number of nickels is 1 coin.