Somebody else had asked this question and they said it was 35 so your best bet is to go with 35
Making the assumption that your problem looks like this,

we use the distributive property to multiply:
It would be: 3(x + 21) ≤ -26
3x + 21 ≤ -26
3x ≤ -47
x < -47/3
In short, Your Answer would be -47/3 or 15.67
Hope this helps!