Answer:
Step-by-step explanation:
Ill try to break this down, simply:
When we talk about percentages we are talking about how much part of something we have and the percent sign is a just a symbol representing that.
Lets say we have 2 out of 10 apples and we need to convert this to a percentage
First think about how many apples we have in total... and that would be 10, and then how many apples we currently have being 2:
So if we put the part that we have over the whole thing we get:
So now lets turn this into a decimal, when its something over 10 its really easy, all we have to do is move the decimal back one place!
So we have 2 and if we move the decimal back one place we get .2 or 0.2
Now we have our decimal, to convert this into a percentage all we have to do is multiply our decimal by 100
So:
0.2 x 100 = 20%
All you do when you multiply by 100 is move the decimal back over 2 places one place for each zero so:
0.2 --> 2. --> 20.
Which gives us again 20%
You can solve this in two ways.
First way:
Let’s find out how many my friend makes in one minute.
12/5=2.4
He makes 2.4 in one minute. Let’s multiply that by 20 to find what he makes in 20 minutes.
2.4•20=48
My friend made 48 desserts.
Second way:
Let’s make a ratio.
12 desserts:5 minutes
X desserts: 20 minutes
Whatever you do to one side, you have to do to the other. Since you are multiplying the minutes by 4, you have to multiply the desserts by 4.
12•4=48
So, my friend made 48 desserts.
Tell me if this helps!!!
Answer: 63 degrees.
Step-by-step explanation:
Angles in a triangle add up to 180 degrees.
Therefore: 54 + y + y = 180
So 54 + 2y = 180
So 2y = 126
Therefore y = 63 degrees.
Answer:
10 and 15
Step-by-step explanation:
Let 'x' and 'y' are the numbers we need to find.
x + y = 25 (two numbers whose sum is 25)
(1/x) + (1/y) = 1/6 (the sum of whose reciprocals is 1/6)
The solutions of the this system of equations are the numbers we need to find.
x = 25 - y
1/(25 - y) + 1/y = 1/6 multiply both sides by 6(25-y)y
6y + 6(25-y) = (25-y)y
6y + 150 - 6y = 25y - (y^2)
y^2 - 25y + 150 = 0 quadratic equation has 2 solutions
y1 = 15
y2 = 10
Thus we have
:
First solution: for y = 15, x = 25 - 15 = 10
Second solution: for y = 10, x = 25 - 10 = 15
The first and the second solution are in fact the same one solution we are looking for: the two numbers are 10 and 15 (since the combination 10 and 15 is the same as 15 and 10).
Answer:
-1
Step-by-step explanation:
Given the equation:
Substitute 
into this equation:
Subtract 4:
