If logab = x which statement is not necessarily true?

Look at attachment. has all info needed. need

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

Hector and alex traded video games. alex gave hector one fourth of his video games in exchange for 6 video games. then he sold 3 video games and gave 2 video games to his brother. alex ended up with 16 video games. how many video games did alex have when he started?