Update the question so it's on-topic for Mathematics Stack Exchange. Closed 4 years ago. How many words can be made by using the letters of the word ENGLAND such that words begin and end with a vowel? I couldn't understand how come the answer to this question is 120
Answer:
x + Y = 39 or x = 39-y
20x + 50y = 1.40
20 (39 - y) + 50y = 11.40
7.80 - 20y + 50y = 11.40
30y = 11.40 - 7.80
30y = 3.60
y = 3.60/30
y = 12 50p coins were collected.
x = 39 - 12 = 27 20p coins were collected.
Proof:
20*27 + 50*12 = 11.40
5.40 + 6 = 11.40
11.40 = 11.40
I hope it helps.
Answer:
show in attachment
Step-by-step explanation:
Here is how we get the answer....
First, replace f(x) with y . ...
Replace every x with a y and replace every y with an x .
Solve the equation from Step 2 for y . ...
Replace y with f−1(x) f − 1 ( x ) . ...
Verify your work by checking that (f∘f−1)(x)=x ( f ∘ f − 1 ) ( x ) = x and (f−1∘f)(x)=x ( f − 1 ∘ f ) ( x ) = x are both true.
