\(\frac{637.527-189}{526.637+448}=1\)

Ta có:

\(\dfrac{637.527-189}{526.637+448}=\dfrac{637.\left(526+1\right)-189}{526.637+448}=\dfrac{637.526+637-189}{526.637+448}=\dfrac{637.526+448}{526.637+448}=1\)

**** cho minn nhe

637.527-189                 =637.526+637.1-189               =637.526+448            =1

526.637+448                       637.526+448                     637.526+448

\(a)\)\(\left(1989.1990+3978\right)\div\left(1992.1991-3984\right)\)

\(=\)\(\left(1989.1990+1989.2\right)\div\left(1992.1991-1992.2\right)\)

\(=\)\(\left[1989.\left(1990+2\right)\right]\div\left[1992.\left(1991-2\right)\right]\)

\(=\)\(\left(1989.1991\right)\div\left(1992.1989\right)\)

\(=\)\(1\)

\(b)\)\(\left(637.527-189\right)\div\left(526.637+448\right)\)

\(=\)\(\left[637.\left(526-1\right)-189\right]\div\left(526.637-448\right)\)

\(=\)\(\left[637.526+\left(637-198\right)\right]\div\left(637.526-448\right)\)

\(=\)\(\left(636.526+448\right)\div\left(637.526-448\right)\)

\(=\)\(1\)

\(=\dfrac{637.\left(526+1\right)-189}{526.637+448}=\dfrac{637.526+637-189}{526.637+446}=\dfrac{637.526+448}{526.637+448}=1\)

\(\left(637.527-189\right):\left(526.637+448\right)\)

\(=\left(335699-189\right):\left(335062+448\right)\)

\(=335510:335510\)

\(=1\)

1 tấn +100km³+1km²+1000m=

giúp mình với help me

=335918.116

(thực hiện phép nhân, chia trước nha)

Học tốt

Ờ Phân à

42x13-22x5+42x7-15x22

= 42 x (13+7) - 22 x (5+15)

= 42 x 20 - 22 x 20

= 20 x (42 - 22)

= 20 x 20 = 400

___

37x39+78x74+13x85+52x55

= 37 x 3 x 13 + 13 x 6 x 74 + 13 x 85 + 13 x 4 x 55

= 13 x (37 x 3+ 74 x 6+ 85 + 4 x 55)

= 13 x (111 + 444 + 85 + 220)

= 13 x 860 = 11180

(637x527-189):(526x637+448)

= (637 x 526 + 637 - 189): (526 x 637 + 448)

= (637 x 526 + 448) : (526 x 637 + 448) = 1