\(\frac{16x17-5}{16x16+11}=\frac{16x16+16-5}{16x16+11}=1\)

\(\frac{4}{3x7}+\frac{5}{7x12}+\frac{1}{12x13}+....+\frac{3}{20x23}\)

=\(\frac{1}{3}-\frac{1}{7}+\frac{1}{7}-\frac{1}{12}+\frac{1}{12}-\frac{1}{13}+...+\frac{1}{20}-\frac{1}{23}\)

=\(\frac{1}{3}-\frac{1}{23}=\frac{20}{69}\)

a) \(\frac{16\cdot17-5}{16\cdot16+11}\)

= \(\frac{16\cdot16+16-5}{16\cdot16+11}\)

= \(\frac{16\cdot16+11}{16\cdot16+11}=1\)

\(\frac{16.17-5}{16.16+11}\)

\(=\frac{16.16+16-5}{16.16+11}\)

\(=\frac{16.16+11}{16.16+11}\)

\(=1\)

\(\frac{16\cdot17-5}{16\cdot16+11}\)

\(=\frac{16\cdot17-5}{16\cdot17-16-11}\)

\(=\frac{16\cdot17-5}{16\cdot17-5}\)

\(=1\)

mk ko copy của Trần Thùy Dung nhé

\(\frac{16.17-5}{16.16+11}\)

\(=\frac{17-5}{16+11}\)

\(=\frac{12}{27}\)

Bài làm

      \(\frac{16x17-5}{16x16+11}\)

\(=\frac{272-5}{256+11}\)

\(=\frac{267}{267}\)

\(=1\)

# Học tốt #

\(\frac{16.17-5}{16.16+11}\)

\(=\frac{16.\left(16+1\right)-5}{16^2+11}\)

\(=\frac{16^2+16-5}{16^2+11}\)

\(=\frac{16^2+11}{16^2+11}\)

\(=1\)

(Nhớ k cho mình với nhé!)

 \(\frac{16x17-5}{16x16+11}\)

=\(\frac{16x\left(16+1\right)-5}{16x16+11}\)

=\(\frac{16x16+16x1-5}{16x16+11}\)

= \(\frac{16x16+11}{16x16+11}\)

= 1 ( vì TS = MS )

\(\frac{16\times17-5}{16\times16+11}=\frac{16\times\left(16+1\right)-5}{16\times16+11}=\frac{16\times16+16-5}{16\times16+11}=\frac{16\times16+11}{16\times16+11}=1\)

Trả lời

\(\frac{16\times17-5}{16\times16+11}=\frac{16\times\left(16+1\right)-5}{16\times16+11}\)

                             \(=\frac{16\times16+16-5}{16\times16+11}\)

                             \(=\frac{16\times16+11}{16\times16+11}\)

                              \(=1\)

a: A=16*16+16-5=16*16+11

=>A=B

b: A=2000*2000=2000^2

B=1998*2002=(2000-2)(2000+2)=2000^2-4

=>A<B

d: B=(2020-1)(2020+1)=2020^2-1

=>B<A

a) Mẫu số chung = BCNN(11, 7) = 77

Thừa số phụ: 77: 11= 7; 77:7 = 11.

Ta có:

\(\begin{array}{l}\frac{7}{{11}} + \frac{5}{7} = \frac{{7.7}}{{11.7}} + \frac{{5.11}}{{7.11}}\\ = \frac{{49}}{{77}} + \frac{{55}}{{77}} = \frac{{104}}{{77}}\end{array}\).

b) Mẫu số chung = BCNN(20, 15)= 60 

Thừa số phụ: 60:20 = 3; 60:15 = 4

Ta có:

\(\begin{array}{l}\frac{7}{{20}} - \frac{2}{{15}} = \frac{{7.3}}{{20.3}} - \frac{{2.4}}{{15.4}}\\ = \frac{{21}}{{60}} - \frac{8}{{60}} = \frac{{13}}{{60}}\end{array}\).