Alright, lets get started.
The ages of all four sisters will be = x, x+2, x+4, x+6
As per given in question, two times of youngest sister age exceeds the oldest sister age by 30 means

Simplifying the equation



So this is the age of youngest sister.
So, age of oldest sister will be 
Hene the age of oldest sister is 42 years. : Answer
Hope it will help :)
Answer:
6 red cars
Step-by-step explanation:
Multiply the number of cars by the percent that are red
50 * 12%
50 * .12
6
On the last day she needs to travel 64 miles
Answer:
f(3x) - 2g(x+1) = 12x - 5
Step-by-step explanation:
You've got f[g(x)] and g[f(x)] correct
However, f(3x) means substitute 3x for x in f(x):
f(3x) = 2(3x) - 3
⇒ f(3x) = 6x - 3
2g(x+1) = 2[4 - 3(x + 1)]
⇒ 2g(x+1) = 2[4 - 3x -3]
⇒ 2g(x+1) = 2[1 - 3x]
⇒ 2g(x+1) = 2 - 6x
f(3x) - 2g(x+1) = (6x - 3) - (2 - 6x)
⇒ f(3x) - 2g(x+1) = 12x - 5