Question

Aflati-l pe ,,a,, din realitatile:

(287:a-1):8-30:10=200:100 (630:5+a):7+18x4=900:9-8

Answer 1

(287:a-1):8-30:10=200:100
(287:a-1):8-3=2
(287:a-1):8=2+3
(287:a-1):8=5
287:a-1=5x8
287:a-1=40
287:a=40+1
287:a=41
a=287:41
a=7

(630:5+a):7+18x4=900:9-8 
(126+a):7+72=100-8 
(126+a):7+72=92 
(126+a):7=92-72
(126+a):7=20
126+a=20x7
126+a=140
a=140-126
a=14

Answer 2

(287:a-1):8-3=2
(287:a-1):8=2+3=5
287:a-1=5x8=40
287:a=40+1=41
a=287:41=7

(126+a):7+18x4=100-8
(126+a):7+72=92
(126+a):7=92-72=20
126+a=20x7=140
126+a=140
a=140-126=14