m(12 + 7n)
The expression 12m + 12n is equal to 12 times the sum of m and n. This expression cannot be simplified further unless there are like terms that can be combined. If m and n are like terms, then the expression can be further simplified by factoring out the common factor of 12 to get 12(m + n).
18m-7+12m
An algebraic expression
-6
If you mean: 12(3+m) then it is the same as 36+12m
12(m+n)
30m-7
Assuming you mean 12m + 12n, you can use the distributive property to take out the common factor 12.
(m - 2)(m - 10)
(3+2) (4+48)
1m = 100cm, therefore 12m = 1200cm. 12m is > 120 cm