a) 5

b) -10/7

c) 1/9

Chúc học tốt!!!!

a,\(\frac{2^3.3^4}{2^2.3^2.5}=\frac{2.3^2}{5}=\frac{2.9}{5}=\frac{18}{5}\)

b, \(\frac{2^4.5^2.11^2.7}{2^3.5^3.7^2.11}=\frac{2.11}{5.7}=\frac{22}{35}\)

c,\(\frac{1998.1990+3978}{1992.1991-3984}=\frac{18.111.1990+18.221}{24.83.1991-166.24}\)

                                           \(=\frac{18.\left(111.1990+221\right)}{24.\left(83.1991-166\right)}\)

                                           \(=\frac{3.221111}{4.165087}=\frac{221111}{4.55029}=\frac{221111}{220116}\)

                                           \(\)

A = ( 71 + x ) - ( -24 - x ) + ( -35 - x )

= 71 + x - ( -24 ) + x + ( -35 ) + x 

= 71 - ( -24 ) + ( -35 ) + x . 3

= 60 + 3x 

= 3 ( 20 + x ) 

B = x - 34 - [ ( 15 + x ) - ( 23 - x ) ]

= x - 34 - [ 15 + x - 23 + x ]

= x - 34 - ( 15 - 23 ) - 2x

= x - 34 - ( -8 ) - 2x

= x - 26 - 2x 

= ( -x )  - 26 

C ) tương tự 

a. x+60

b. -x-26

c.10

\(-\frac{5}{10}=-\frac{1}{2}\)

\(\frac{18}{33}=\frac{6}{11}\)

\(\frac{19}{57}\)

\(\frac{-36}{-12}=\frac{3}{2}\)

-1/2

-6/11

1/3

3

Hok tốt!

MK lm bài 1:

\(\left(a-b\right)\left(a+b\right)=a^2+ab-ab-b^2=a^2-b^2\)

Bài 1:

\(\left(a-b\right)\left(a+b\right)=a^2+ab-ab-b^2\)

\(=a^2-b^2\)

a)  - 1

b)  1 2