a) 39 . (x - 5 ) = 0
x - 5 = 0 : 39
x - 5 = 0
x = 0 + 5
x = 5
b) ( 30 - x ) . 4 = 92
30 . x = 92 : 4
30 . x = 23
x = 23 : 30
x =\(\frac{23}{30}\)
a) 39 . ( x - 5 ) = 0
x - 5 = 0 : 39
x - 5 = 0
x = 0 + 5
x = 5
b) ( 30 - x ) . 4 = 92
30 - x = 92 : 4
30 - x = 23
x = 30 - 23
x = 7
a) 39 . ( x - 5 ) = 0
x - 5 = 0 : 39
x - 5 = 0
x = 0 + 5
x = 5
b) ( 30 - x ) . 4 = 92
30 - x = 92 : 4
30 - x = 23
x = 30 - 23
x = 7