Well, is namely their difference, so, let's first convert the mixed fractions to "improper", and subtract.
Answer:
Plug x-7 in for y, in the bottom equation.
x - 7 = 2 + 2x - 4
x - 7 = 2x - 2
x = 2x + 5
-x = 5
x = -5
The correct answer is 3/13. Divided both by 5.
15/65
3/13
Answer:
34,220
Step-by-step explanation:
Because order doesn't matter, but the numbers can't be repeated, we need to find the number of combinations where 3 individual numbers can be chosen out of 60 possible numbers using the binomial coefficient:

Thus, Elias can make 34,220 unique 3-number codes given 60 different numbers.