Question

use mental math to evaluate the expression 6(31)+6(4)-6(15)

Answer 1

The factor six is in common, so I snap to 31+4-15, or 35-15 which is 20.  This then needs to be multiplied by the six I ignored before, so the answer is 120.

Answer 2

so this is what you would do first do 6 x 31 then do not add nd go to 6 x 4 then go to 6 x 15 when youve got ur answers for those you go back to the beggining,after that you add 6 x 31 and 6 x 4 and when youve got your answer 210 you -(subtract) it with 6 x 15 witch should be 90 so you would get 120 as your answer or you could do it the easier way which is                                                186 + 24 - 90 = 120