Help please, Which expression does not belong? Explain your reasoning.

My best answer is option number 4.

Step-by-step explanation:

Because the first 3 answers follow a specific pattern in addition and division, i.e. they only go up to 4 different numbers, whereas with the 4th option, that changes. Not only that, but if you look closely, the 4th option adds 6 to itself 5 times, that's the same as 6x5, which equals 30, so if you divide 30 by 5, its almost pointless seeing as how you already know it's gonna get you 6.

2x+18+5x-9

2x+5x18-9

7x+9

7. 7

x= 1.4

hope it helps