20 : 5 - 2020

= 4 - 2020 

= -2016

20 : 5 - 2020

= 4 - 2020

= -2016

=4-2020

=4+(-2020)

=-2016

20 – [30 – (5 – 1)2] = 20 – (30 – 42) = 20 – (30 – 16) = 20 – 14 = 6

5²⁰ : (5¹⁵.6 + 5¹⁵.19)

= 5²⁰ : [5¹⁵(6 + 9)]

= 5²⁰ : (5¹⁵.15)

= \(\frac{625}{3}\)

\(5^{20}:\left(5^{15}.6+5^{15}.19\right)=5^{20}:\left[5^{15}\left(6+19\right)\right]\)

\(=5^{20}:\left(5^{15}.25\right)=5^{20}:\left(5^{15}.5^2\right)=5^{20}:5^{17}\)

\(=5^3=125\)

Bài làm

   5²⁰ : ( 5¹⁵ . 6 + 5¹⁵ . 19 )

= 5²⁰ : [ 5¹⁵ . ( 6 + 19 ) ]

= 5²⁰ : [ 5¹⁵ . 25 ]

= 5²⁰ : [ 5¹⁵ . 5² ]

= 5²⁰ : 5¹⁵ 

= 5⁵ 

= 3125

# Học tốt #

#include <bits/stdc++.h>
using namespace std;
char a;
int main()
{
    cin>>a;
    if (a=='S') cout<<"50";
    else cout<<"600";
    return 0;
}

4 x 5 + 10 = 20 + 10 = 30

3 x 9 – 20 = 27 – 20 = 7

\(=\left(\sqrt{9.5}-\sqrt{4.5}+\sqrt{5}\right):\sqrt{6}\\ =\left(3\sqrt{5}-2\sqrt{5}+\sqrt{5}\right):\sqrt{6}\\ =\dfrac{2\sqrt{5}}{\sqrt{6}}\\ =\dfrac{\sqrt{2}.\sqrt{2}.\sqrt{5}}{\sqrt{2}.\sqrt{3}}\\ =\dfrac{\sqrt{10}}{\sqrt{3}}=\dfrac{\sqrt{30}}{3}\)

\(\left(\sqrt{45}-\sqrt{20}+\sqrt{5}\right):\sqrt{6}\\ =\left(\sqrt{9.5}-\sqrt{4.5}+\sqrt{5}\right):\sqrt{6}\\ =\left(3\sqrt{5}-2\sqrt{5}+\sqrt{5}\right):\sqrt{6}\\ =2\sqrt{5}:\sqrt{6}\\ =2\sqrt{5}.\dfrac{1}{\sqrt{6}}\\ =\dfrac{2\sqrt{5}}{\sqrt{6}}\\ =\dfrac{2\sqrt{5}.\sqrt{6}}{6}\\ =\dfrac{1}{3}.\sqrt{30}\\ =\dfrac{\sqrt{30}}{3}\)

=1

1

\(\left[\left(7^5:7^3+3^3\cdot20\right)^0\right]^{2016}\)

\(=1^{2016}\)

=1

Lời giải:
\(\frac{20^4.15^5}{12^5.25^4}=\frac{(2^2.5)^4.(3.5)^5}{(2^2.3)^5.(5^2)^4}=\frac{2^8.5^4.3^5.5^5}{2^{10}.3^5.5^8}\)

\(=\frac{2^8.5^9.3^5}{2^{10}.3^5.5^8}=\frac{2^8.5^8.5.3^5}{2^8.2^2.3^5.5^8}=\frac{5}{2^2}=\frac{5}{4}\)