a) Đề:.........
<=> 1995 - y = 663 x 3
<=> 1995 - y = 1989
<=> y = 1995 - 1989
<=> y = 6
Vậy y = 6
b) Đề:..........
<=> y - 3 = 1995 - 662
<=> y - 3 = 1333
<=> y = 1333 + 3
<=> y = 1336
Vậy y = 1336
c) Đề:.............
<=> 5 x (y + 5) = 165
<=> y + 5 = 165 : 5
<=> y + 5 = 33
<=> y = 33 - 5
<=> y = 28
Vậy y = 28
d) Đề:..........
<=> 5 x y + 5 = 165
<=> 5 x y = 165 - 5
<=> 5 x y = 160
<=> y = 160 : 5
<=> y = 32
Vậy y = 32
a (1995- y) :3 = 662
1995 - y= 662 x 3
1995- y = 1968
y = 27
b 1995 - y : 3 =662
y : 3 = 1995 -662
y : 3 = 333
y = 333 x 3
y =999
c 5x [y+ 5] =165
y + 5 =165 : 5
y + 5 = 33
y = 33 - 5
y = 28
d 5 * y +5 =6825 -6660
5* y+ 5= 165
5* y = 165 - 5
5* y = 160
y = 160 : 5
y =32
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