a, ( 5 x y - 15 ) : 5 = 0
( 5 x y - 15 ) = 0 x 5
( 5 x y - 15 ) = 0
5 x y = 0 + 15
5 x y = 15
y = 15 : 5
y = 3
b. 14 x ( y - 7 ) = 210
( y - 7 ) = 210 : 14
( y - 7 ) = 15
y = 15 + 7
y = 22
c. 84 - 4 x ( 2 x y + 1 ) = 48
4 x ( 2 x y + 1 ) = 84 - 48
4 x ( 2 xy + 1 ) = 36
( 2 x y + 1 ) = 36 : 4
( 2 x y + 1 ) = 9
2 x y = 9 - 1
2 x y = 8
y = 8 : 2
y = 4
d. 5 x y - 2009 = 1201
5 x y = 1201 + 2009
5 x y = 3210
y = 3210 : 5
y = 642
a. (5.y-15):5=0
=> 5.y-15 = 0
=> 5.y = 15
=> y = 3
b. 14.(y-7) = 210
=> y-7 = 15
=> y = 22
c. 84-4.(2.y+1)=48
=> 4.(2.y+1) = 36
=> 2.y+1 = 9
=> 2.y = 8
=> y = 4
d) 5.y-2009 = 1201
=> 5.y = 3210
=> y = 642
a) (5.y-15):5=0
5.y-15=0.5
5.y-15=0
5.y=15
y=15:5
y=3
b) 14.(y-7)=210
y-7==210:14
y-7=15
y=15+7
y=22
c) 84-48.(2.y+1)=48
4.(2.y+1)=84-48=36
2y+1=36:4=9
2y=9-1=8
y=8:2
y=2
d)5.y-2009=1201
5.y=2009+1202=3210
y=3210:5
y=642
chúc bạn học tốt nha, ủng hộ mk với nha
a) \(\left(5\times y-15\right)\div5=0\)
\(5\times y-15=0\times5\)
\(5\times y-15=0\)
\(5\times y=0+15\)
\(5\times y=15\)
\(y=15\div5\)
\(y=3\)
b) \(14\times\left(y-7\right)=210\)
\(y-7=210\div14\)
\(y-7=15\)
\(y=15+7\)
\(y=22\)
c) \(84-4\times\left(2\times y+1\right)=48\)
\(4\times\left(2\times y+1\right)=84-48\)
\(4\times\left(2\times y+1\right)=36\)
\(2\times y+1=36\div4\)
\(2\times y+1=9\)
\(2\times y=9+1\)
\(2\times y=10\)
\(y=10\div2\)
\(y=5\)
d) \(5\times y-2009=1201\)
\(5\times y=1201+2009\)
\(5\times y=3210\)
\(y=3210\div5\)
\(y=642\)
~ HOK TỐT ~
