Answer:
The inverse of the function is 
.
Step-by-step explanation:
The function provided is:
Let 
.
Then the value of <em>x</em> is:
For the inverse of the function, 
.
⇒
Compute the value of ![f[f^{-1}(x)]](https://tex.z-dn.net/?f=f%5Bf%5E%7B-1%7D%28x%29%5D)
as follows:
![f[f^{-1}(x)]=f[\frac{x-5}{3}]](https://tex.z-dn.net/?f=f%5Bf%5E%7B-1%7D%28x%29%5D%3Df%5B%5Cfrac%7Bx-5%7D%7B3%7D%5D)
![=3[\frac{x-5}{3}]+5\\\\=x-5+5\\\\=x](https://tex.z-dn.net/?f=%3D3%5B%5Cfrac%7Bx-5%7D%7B3%7D%5D%2B5%5C%5C%5C%5C%3Dx-5%2B5%5C%5C%5C%5C%3Dx)
Hence proved that ![f[f^{-1}(x)]=x](https://tex.z-dn.net/?f=f%5Bf%5E%7B-1%7D%28x%29%5D%3Dx)
.
Compute the value of ![f^{-1}[f(x)]](https://tex.z-dn.net/?f=f%5E%7B-1%7D%5Bf%28x%29%5D)
as follows:
![f^{-1}[f(x)]=f^{-1}[3x+5]](https://tex.z-dn.net/?f=f%5E%7B-1%7D%5Bf%28x%29%5D%3Df%5E%7B-1%7D%5B3x%2B5%5D)
Hence proved that ![f^{-1}[f(x)]=x](https://tex.z-dn.net/?f=f%5E%7B-1%7D%5Bf%28x%29%5D%3Dx)
.
Elvira (e) is 5 years older than Morton (m)
e = m + 5
Morton (m) is twice as old as Michelle (c)
m = 2c
The combined total of their ages is 85
e + m + c = 85
We want m at the end so let's write everything in terms of m.
e = m + 5
c = m/2
85 = e + m + c = m+5 + m + m/2 = 5 + (5/2) m
m = (2/5) (85 - 5) = 32
Answer: 32 years old
Check:
That makes Elvira 37 and Michele 16, total 32+37+16=85, good
25.8 - 5 = 20.8
20.8 divide by 2.5 = 8.32
so it should be 8
Answer:
13,600 
Step-by-step explanation:
(h = 7, l = 6, w = 2) 10
70, 60, 20
2(h × w) + 2(h × l) + 2(w × l)
= 2(70 × 20) + 2(70 × 60) + 2(20 × 60)
= 2(1400) + 2(4200) + 2(1200)
= 2800 + 8400 + 2400
= 13,600
Hello!
You can solve this algebraically
7 - 5y = 3y - 17
Add 5y to both sides
7 = 8y - 17
Add 17 to both sides
24 = 8y
Divide both sides by 8
3 = y
The answer is 3
Hope this helps!
