800 - 540 : 9 - 7 65300 ∙ 7= 800- 60 - 5357100=5356240
56000 + 4072 ∙ 5 - 20360 9048 ∙ 5= 56000+20360-1018045240=1017968880
A-2a+1-3a
-a+1-3a
-4a+1
-4*1,2+1
-4,8+1=-3,8
-4.2x*(-6y) = 25.2xy
8m + 5p - 13m - p= -5m + 4p
k - (17 - k) + (-k + 30) = k - 17 + k - k + 30 = k + 13
-6*(4 + a) + 8*(a-6) = -24 - 6a + 8a - 48 = -72 + 2a
-5+9+12+х 16+х
-------------- = ----------- = 9
4 4
16+х=9•4
16+х=36
х=36-16
х=20