gúp mik với ạ
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
27: \(\sqrt{\dfrac{81}{25}}-\dfrac{1}{5}\left(-3+\sqrt{16}\right)^{20}\cdot\left(-2\right)^3\)
\(=\dfrac{9}{5}-\dfrac{1}{5}\cdot\left(-8\right)\)
\(=\dfrac{9}{5}+\dfrac{8}{5}=\dfrac{17}{5}\)
28: \(\sqrt{\sqrt{16}}-\sqrt{\sqrt{81}}=2-3=-1\)
\(4,=\left(a-3-2\right)\left(a-3+2\right)=\left(a-5\right)\left(a-1\right)\\ 5,=\left(a-2b+b\right)\left(a-2b-b\right)=\left(a-b\right)\left(a-3b\right)\\ 6,=\left(4a-3b\right)\left(16a^2+12ab+9b^2\right)\)
1. a2 - 4b2
= a2 - (2b)2
= (a - 2b)(a + 2b)
2. 16a2 - b4
= (4a)2 - (b2)2
= (4a - b2)(4a + b2)
3. 4a4 - 81b4
= (2a2)2 - (9b2)2
= (2a2 - 9b2)(2a2 + 9b2)
4. (a - 3)2 - 4
= (a - 3)2 - 22
= (a - 3 - 2)(a - 3 + 2)
= (a - 5)(a - 1)
5. (a - 2b)2 - b2
= (a - 2b - b)(a - 2b + b)
= (a - 3b)(a - b)
6. 64a3 - 27b3
= (4a)3 - (3b)3
= (4a - 3b)(16a2 + 12ab + 9b2)
#include <iostream>
using namespace std;
int main()
{
int a,b,c,kt;
cout<<"Nhap a=";
cin>>a;
cout<<"Nhap b=";
cin>>b;
cout<<"Nhap c=";
cin>>c;
if ((a>0) and (b>0) and (c>0) and (a+b>c) and (a+c>b) and (b+c>a))
{
kt=0;
if (a*a==b*b+c*c) kt=1;
if (b*b==a*a+c*c) kt=1;
if (c*c==a*a+b*b) kt=1;
if ((a==b) and ((a<c) or (a>c)) and ((b<c) or (b>c))) kt=2;
if ((b==c) and ((b<a) or (b>a)) and ((c<a) or (c>a))) kt=2;
if ((c==a) and ((c<b) or (c>b)) and ((a<b) or (a>b))) kt=2;
if ((a==c) and (b==c)) kt=3;
if (kt==0) cout<<"Day la tam giac thuong";
if (kt==1) cout<<"Day la tam giac vuong";
if (kt==2) cout<<"Day la tam giac can";
if (kt==3) cout<<"Day la tam giac deu";
if ((kt==1) and (kt==2) ) cout<<"Day la tam giac vuong can";
}
else cout<<"Day khong la ba canh trong mot tam giac";
return 0;
}
sai
10 - 3 =7
21-9 =12
DT : 9+3+7+12+21+10 = 62 CM2
Đ / S :62 CM2
1. A
2. A
3. C
4. B
5. C
6. D
7. B
8. B
9. D (stay in shape: giữ dáng)
10. C