Răspuns:
Explicație pas cu pas:
74 × 7 - m = 64
518 - m = 64
m = 518 - 64
m = 454
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94 × 7 : m = 2
658 : m = 2
m = 658 : 2
m = 329
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596 + 242 - d = 210
838 - d = 210
d = 838 - 210
d = 628
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( a + 139 ) - 12 : 3 × 15 = 627
( a + 139 ) - 4 × 15 = 627
( a + 139 ) - 60 = 627
a + 139 = 627 + 60
a + 139 = 687
a = 687 - 139
a = 548
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213 - ( 230 - 5 × a ) : 7 = 183
( 230 - 5 × a ) : 7 = 213 - 183
( 230 - 5 × a ) : 7 = 30
230 - 5 × a = 30 × 7
5 × a = 230 - 210
5 × a = 20
a = 20 : 5
a = 4
