There would be 35 rulers.
In order to solve this, use cross multiplication.
6/10 = 21/x -----> cross multiply
10*21 = 6*x
210 = 6x
35 = x
Its the last one because 10 times 1 is 10 and 0 plus 10 still gives you 10
Please write (x4 – 2) ÷ (x + 1) as <span>(x^4 – 2) ÷ (x + 1).
We can find the remainder using synth. div. as follows:
_________________
-1 / 1 0 0 0 -2
-1 1 -1 1
------------------------------
1 -1 1 -1 -1
The remainder is -1.</span>
You would write it 2=10(20+2)