1,           53/51 + 1,75 + 61/8 + 41/4 + 3,875 - 3,4

              53/51 + 7/4 + 61/8 + 41/4 + 31/8 - 17/5

              53/51 + 7/4 + 61/8 + 31/8 + 41/4 - 17/5

              53/51 + 7/4 + 23/2 + 41/4 - 17/5

              53/51 + 7/4 + 41/4 + +23/2-17/5

              53/51 + 12 + 41/4 + 23/2

              =         7097/204

a) \(\frac{2}{3}.\left(\frac{1}{3}+\frac{2}{5}\right)=\frac{2}{3}.\frac{11}{15}=\frac{22}{45}\)

b) 24+25+26+...+99+100

= (100+24).77:2

= 124.77:2

= 4774

c) \(\frac{16.17-5}{16.16+11}=\frac{16.16+(16-5)}{16.16+11}=\frac{16.16+11}{16.16+11}=1\)

d) \(\frac{5}{80}+\frac{5}{90}+\frac{5}{150}+\frac{5}{210}+\frac{5}{270}\)

\(=\frac{1}{16}+\frac{1}{18}+\frac{1}{30}+\frac{1}{42}+\frac{1}{54}\)

\(=\frac{2929}{15120}\)

a)=\(\frac{2}{3}.\left(\frac{5}{15}+\frac{6}{15}\right)\)

= \(\frac{2}{3}.\frac{11}{15}=\frac{22}{45}\)

d) = 5.(\(\frac{1}{80}+\frac{1}{90}+\frac{1}{150}+\frac{1}{210}+\frac{1}{270}\))

= 50........

kq là tự tính:)))))

30,5⁰ = \(30\frac{1}{2}\)độ = 30 độ 30 phút = 1830 phút

60,75⁰ = \(60\frac{3}{4}\)độ = 60 độ 45 phút = 3645 phút

90,2⁰ = \(90\frac{1}{5}\)độ = 90 độ 12 phút = 5412 phút

45,15⁰ = \(45\frac{3}{20}\)độ = 45 độ 9 phút = 2709 phút.

30,5^o = 30\(\frac{1}{2}\) độ = 30^o 30' =1830'

60,75⁰ = 60\(\frac{3}{4}\)độ = 60^o 45' = 3645'

90,2^o = 90 \(\frac{1}{5}\)độ = 90⁰ 12' = 5412'

45,15^o = 45\(\frac{3}{20}\)độ = 45^o 9' = 2709'

k cho mk nha

quá dễ                                 

a) \(15.4=15.\left(2.2\right)=\left(15.2\right).2=30.2=60\)

\(25.12=25.\left(2.6\right)=\left(25.2\right).6=50.6=300\)

\(125.16=125.\left(2.8\right)=\left(125.8\right).2=1000.2=2000\)

b) \(25.12=25.\left(10+2\right)=25.10+25.2=250+50=300\)

\(34.11=34.\left(10+1\right)=34.10+34.1=340+34=374\)

\(47.101=47.\left(100+1\right)=47.100+47.1=4700+47=4747\)

Chúc em học tốt!!!

BẰNG 276 NHÉ 

bn có thể ns cách làm ko (tính nhanh)

a: \(20-\left[30-\left(5-1\right)^2\right]\)

\(=20-\left[30-4^2\right]\)

\(=20-14=6\)

b: \(71+\dfrac{50}{5+3\left(57-6\cdot7\right)}\)

\(=71+\dfrac{50}{5+3\cdot\left(57-42\right)}\)

\(=71+\dfrac{50}{5+3\cdot15}=71+\dfrac{50}{50}=72\)

c: \(4\cdot\left\{270:\left[50-\left(2^5+45:5\right)\right]\right\}\)

\(=4\cdot\left\{270:\left[50-32-9\right]\right\}\)

\(=4\cdot\left\{\dfrac{270}{50-41}\right\}=4\cdot\dfrac{270}{9}=4\cdot30=120\)

d: \(411-\left[\dfrac{\left(107+3\right)}{5}-2^2\right]\)

\(=411-\left[\dfrac{110}{5}-4\right]\)

=410-22+4

=410-18

=392

e: \(450-5\left[3^2\left(7^5:7^3-41\right)-12\right]+18\)

\(=450-5\left[9\cdot\left(7^2-41\right)-12\right]+18\)

\(=450-5\cdot\left[9\cdot8-12\right]+18\)

=468-5*60

=468-300

=168

f:

\(102-150:\left[18-2\cdot\left(10-8\right)^2\right]+1018^0\)

\(=102-150:\left[18-2\cdot4\right]+1\)

\(=103-\dfrac{150}{18-8}=103-15=88\)

đáp số là 276 nhak bạn