Dung hang dang thuc dang nho de giai bai sau: 742+242-48.74
viet 8 hang dang thuc dang nho
ai dung mk tick cho nha ^-^
\(\left(A+B\right)^2=A^2+2AB+B^2\)
\(\left(A-B\right)^2=A^2-2AB+B^2\)
\(\left(A+B\right)^3=A^3+3A^2B+3AB^2+B^3\)
\(\left(A-B\right)^3=A^3-3A^2B+3AB^2-B^3\)
\(A^2-B^2=\left(A+B\right)\left(A-B\right)\)
\(A^3+B^3=\left(A+B\right)\left(A^2-AB+B^2\right)\)
\(A^3-B^3=\left(A-B\right)\left(A^2+AB+B^2\right)\)
\(\left(A+B+C\right)^2=A^2+B^2+C^2+2AB+2AC+2BC\)
1. (A+B)2 = A2+2AB+B2
2. (A – B)2= A2 – 2AB+ B2
3. A2 – B2= (A-B)(A+B)
4. (A+B)3= A3+3A2B +3AB2+B3
5. (A – B)3 = A3- 3A2B+ 3AB2- B3
6. A3 + B3= (A+B)(A2- AB +B2)
7. A3- B3= (A- B)(A2+ AB+ B2)
8. (A+B+C)2= A2+ B2+C2+2 AB+ 2AC+ 2BC
\(\left(3x+1\right)^2-4.\left(x-2\right)^2\)=
Giai dung nha, ai giai dung mk tick cho
Cung la bai phan tich da thuc thanh nhan tu dung hang dang thuc(cua lop 8)
\(\Leftrightarrow\left(3x-1\right)^2-4^2=0\)
\(\Leftrightarrow\left(3x-1-4\right)\left(3x-1+4\right)=0\)
\(\Leftrightarrow\left(3x-5\right)\left(3x+3\right)=0\Leftrightarrow\orbr{\begin{cases}3x-5=0\\3x+3=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=\frac{5}{3}\\x=-1\end{cases}}}\)
cho dang thuc cam + quyt + nho = 2025+2026+2027 co the thay chu bang cac chu so de co dang thuc dung khong ?
minh nghi la cam quyt nho la ba so tu nhien lien tiep
cho a chia het cho5,bchia het cho 5;chung minh rang (a4-b4) chia het cho5 dung cong thuc "hang dang thuc dang nho" cong thuc3
vì a chia hết cho 5 nên a đồng dư với 0 mod 5
suy ra a^4 đồng dư với 0^5 đồng dư với 0 mod 5(1)
vì b chia hết cho 5 nên b đồng dư với 0 mod 5
suy ra b^4 đồng dư với 0^5 đồng dư với 0 mod 5(2)
từ (1),(2) suy ra a^4-b^4 đồng dư với 0-0=0 mod 5
suy ra a^4-b^4 chia hết cho 5 (đpcm)
cho a khong chia het cho 5,b khong chia het cho 5;chung minh rang:(a4-b4) chia het cho5
Goi y: dung "hang dang thuc dang nho'' cong thuc 3
3.7: Su dung cac hang dang thuc de phan tich cac da thuc sau thanh nhan tu:
a) -y2 + 1/9
b) x4 - 256
c) 9 (x - 3)2 - 4 (x + 1)2
d) 25x2 - 1/81 x2y2
a) \(-y^2+\dfrac{1}{9}\)
\(=-\left(y^2-\left(\dfrac{1}{3}\right)^2\right)\)
\(=-\left(y+\dfrac{1}{3}\right)\left(y-\dfrac{1}{3}\right)\)
b) \(4^4-256\)
\(=4^4-4^4\)
\(=0\)
c) \(9\left(x-3\right)^2-4\left(x+1\right)^2\)
\(=\left(3x-9\right)^2-\left(2x+2\right)^2\)
\(=\left(3x-9+2x+2\right)\left(3x-9-2x-2\right)\)
\(=\left(5x-7\right)\left(x-11\right)\)
\(a,=\left(\dfrac{1}{3}-y\right)\left(\dfrac{1}{3}+y\right)\\ b,=\left(x^2-16\right)\left(x^2+16\right)\\ =\left(x-4\right)\left(x+4\right)\left(x^2+16\right)\\ c,=\left[3\left(x-3\right)-2\left(x+1\right)\right]\left[3\left(x-3\right)+2\left(x+1\right)\right]\\ =\left(3x-9-2x-2\right)\left(3x-9+2x+2\right)\\ =\left(x-11\right)\left(5x-7\right)\\ d,=\left(5x-\dfrac{1}{9}xy\right)\left(5x+\dfrac{1}{9}xy\right)=x^2\left(5-\dfrac{1}{9}y\right)\left(5+\dfrac{1}{9}y\right)\)
Nao nay trong nhung hang dang thuc dang nho
(2x2-8xy+2y2)(x.y)
Tính nhanh: 742 + 242 – 48.74
742 – 48.74 + 242
= 742 – 2.74.24 + 242
= (74 – 24)2
= 502
= 2500
giup minh giai bai toan ve hang dang thuc nha
a <x+y+z+d>mu2
b,<x+y-z-d>mu2