Răspuns:
a - ( 9 • 5 ) = 28
a - 45 = 28
a = 28 + 45
a = 73
a + ( 8 • 4 ) = 70
a + 32 = 70
a = 70 - 32
a = 38
( 8 • 5 ) - a = 2 • 9
40 - a = 18
a = 40 - 18
a = 22
a - ( 7 • 4 ) = 5 • 5
a - 28 = 25
a = 25 + 28
a = 53
( 3 • 5 ) + m = 91
15 + m = 91
m = 91 - 15
m = 76
( 10 • 5 ) - b = 18
50 - b = 18
b = 50 - 18
b = 32
n + ( 4 • 9 ) = 100
n + 36 = 100
n = 100 - 36
n = 64
( 5 • 7 ) + a = 92
35 + a = 92
a = 92 - 35
a = 57