1) 18*20 - x = 90360 - x = 90-x = -270x = 270
2) 720 : 8 + x = 47090 + x = 470x = 380
3) 350 : c = 5 * 10350 = 50c7 = c
4) k : 30 = 60 5k = 30 60 * 5k = 900
1) 18*20 - x = 90
360 - x = 90
-x = -270
x = 270
2) 720 : 8 + x = 470
90 + x = 470
x = 380
3) 350 : c = 5 * 10
350 = 50c
7 = c
4) k : 30 = 60 5
k = 30 60 * 5
k = 900