bài 2:
a)723-(7x-152)=714
(7x-152)=723-714
(7X-152)=9
7x =9+152
7x =161
x =161:7
x =23
vậy......
b)(2x-130):4+213=5^2+193
________________=25+193
________________=218
(2x-130):4 =218-213
(2x-130):4 =5
2x-130 =5.4
2x-130 =20
2x =20+130
__ =150
x =150:2=75
vậy.......
c)(x-6)^2=9
_______=3^2
x-6 =3
x =3+6=9
vậy........
d)5^2x-3-2.5^2=5^2.3
5^2x-3-2.25=25.3
5^2x-3-50=75
5^2x-3 =75+50
________ =125
________ =5^3
suy ra:
2x-3=3
2x =3+3
2x =6
x =6:2=3
vậy.....
e)(5^2+3^2).x+(5^2-3^2).x-50=10^2
(25+9).x+(25-9).x-50=100
34.x+16.x=100+50
__________=150
x.(34+16)=150
x.50=150
x =150:50
x =3
vậy..........
bài 2:
a)12.25+12.81-12.6=12.(25+81-6)=12.100=1200
b)21.44+21.67-21.11=21.(44+67-11)=21.100=2100
c)34.74+34.45-34.19=34.(74+45-19)=34.100=3400
d)25.28+25.88-25.16=25.(28+88-16)=25.100=2500
e)27.91+27.52-27.43=27.(91+52-43)=27.100=2700
f)45.39+45.64-45.3=45.(39+64-3)=45.100=4500
mà nè mấy cái _____ đó là viết lại giống dòng trên nghen
