Explicație pas cu pas:
a) x + 1013 =5025
x= 5025-1013
x=4012
b) 1649 - x =399
x = 1649 - 399
x= 1250
7010+ x = 7226
x= 7266 - 7010
x = 256
x- 445 =1659
x = 1659+445
x = 2014
d) x × 10 = 100
x= 100:10
x= 10
c) 9× x =90
x= 90:9
x= 10
45 : x= 5
x= 45 :5
x= 9
x: 7 =123
x= 123 ×7
x= 861