They are easy to compare if they all have the same common denominator, then you can easily order them by the magnitude of the numerators...
85/10, -67/10, -56/10, 82/10 so now they are easy to compare...so
-6.7, -28/5, 8.2, 17/2
<span>m-3x=2x+p
m-x=p (- 2x on both sides)
-x=p-m (- m on both sides)
answer: x=-p+m (divide -1 on both side)
</span>
Assuming the given is: 5u^7 - 21u^7
Since both algebraic terms are identical (both are using u^7), we can subtract the coefficients directly, as in: 5 - 21 = -16
Therefore, 5u^7 - 21u^7 = -16u^7