Question

a) a first number is 7 greater than a second number. Twice the first number is 4 more than three times the second. Find the numbers

Answer 1

x > 7 + y
2x > 4 + 3y

1st inequality implies: y < x -7
2nd inequality implies y < 2x/3 - 4/3

The slopes of these are different, so they will intersect. They intersect at x=17.
So, for x <= 17, y < x-7 and for x > 17, y < 2x/3 - 4/3.



http://www.wolframalpha.com/input/?i=x+%3E+7+%2B+y%2C+2x+%3E+4+%2B+3y

Let me know if you have any questions.