(637.527-189):(526.637+448)

= \(\frac{637.527-189}{526.637+448}\)

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

=  \(\frac{637.526+637-189}{526.637+448}\)

= \(\frac{637.526+448}{526.637+448}\)

= \(1\)

**** cho minn nhe

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

526.637+448                       637.526+448                     637.526+448

Ta có:

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

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

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

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

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

\(=\)\(1\)

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

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

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

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

\(=\)\(1\)

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

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

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

\(=335510:335510\)

\(=1\)

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

a)=\(\frac{637x\left(526+1\right)-189}{526x637+448}\)

=\(\frac{637x526+637-189}{526x637+448}\)

=\(\frac{637x526+448}{526x637+448}\)

=\(1\)(vì tử số =mẫu số)

b)=\(\frac{\left(134+1\right)x269-133}{134x269+136}\)

=\(\frac{134x269+269-133}{134x269+136}\)

=\(\frac{134x269+136}{134x269+136}\)

=1(vì tử số =mẫu số)

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

\(b=\frac{637.\left(526+1\right)-189}{526.637+448}\)

\(b=\frac{637.526+\left(637-189\right)}{526.637+448}\)

\(b=\frac{637.526+448}{526.637+448}=1\)

Dấu . là nhân nha

\(\frac{637.527-189}{526.637+448}=\frac{637.526+637-189}{526.637+448}=\frac{637.526+448}{526.637+448}=1\)

\(B=\frac{637x527-189}{526x637+448}\)

\(B=\frac{637x\left(526+1\right)-189}{526x637+448}\)

\(B=\frac{637x526+637-189}{526x637+448}\)

\(B=\frac{637x526+448}{526x637+448}=1\)