19
45
-261
12+5+9+10=36/4=9 9 is the Mean of 12, 5, 9, and 10 To find the mean of something, add all the figures and then divide by the number of figures.
It is: 1/3 plus 9/12 = 13/12 or 1 and 1/12 as a mixed number
16+13+12+929+12+941+950
The denominators are equal, so you can just add the numerators exactly. They add up to 9 over 12.
12+9=21 21+15=36 36+13=49 49+6=55
12
12 -9 + x = 3 -9 + x + 9 = 3 + 9 x = 3 + 9 x = 12
19
The numbers are -12, -11, -10 and -9.
12
45
It is: (15-7)*(12-9) = 24
Given: x - 9 > 12. Add 9 to each side, to obtain x > 21.
46. The pattern is add 3 then add 6 then add 9 then add 12 then add 15 ...