We have 26 - 18 = 8; 34 - 26 = 8; 42 - 34 = 8; (an arithmetic progression)
We use the formula an = a1 + (n-1)x8 (the explicit formula)
So, an = 18 + (n-1)x8 ;
Then, an = 8n + 10;
Finally, a52 = 8x52 + 10 = 426 (the 52nd term);
Subtracting mx from both sides, we get y-mx=b
209/12 is 17.41, so 12 goes into 209 17 times.