Answer:
690
Step-by-step explanation:
Put 30 where m is in the expression and do the arithmetic. Or, simpify the expression first, then do the same.
14·30 +30 +17·30 -9·30 = 420 +30 +510 -270 = 690
Simplifying first, you have ...
14m +m +17m -9m = m(14 +1 +17 -9) = 23m
23·30 = 690