a) 91 - x = 90
x = 91 - 90
x = 1
b) x - 73.21 = 73.26
x = 73.26 + 73.21
x = 73.(26 + 21)
x = 73.47
x = 3431
c) 6.(x + 11) = 0
x + 11 = 0 : 6
x + 11 = 0
x = 0 - 11
x = -11
d) 2x - 12 - x = 9
=> 2x - (12 + 9) = x
=> (2 - 1)x = 21
=> x = 21
a) 91 - x = 90
x=91-90
x=1
b) x - 73 . 21 = 73 . 26
x-1533=1898
x=3431
c) 6 . ( x +11 ) = 0
x+11=0
x=-11
d) 2x - 12 - x = 9
x-12=9
x=21
a) 91-x=90
x=91-90
x=1
b) x-73.21=73.26
x-73.21=1898
x=1898+(73.21)
x=3431
c)6.(x+11)=0
x=.......(rỗng)
d)2x-12-x=9
x=21
CHÚC BẠN HỌC TỐT !!