HPT là gì

Hệ phương trình lớp 9 ý

bạn viết rõ ràng ra được ko

mình sẽ giúp bạn

căn  3x-5 + căn 7-3x = 9x mũ 2 -36+38

• (a² + b²)(c² + d²) ≥ (ac + bd)²
• Chứng minh: (a² + b²)(c² + d²) ≥ (ac + bd)² ↔ (ac)² + (ad)² + (bc)² + (bd)² ≥ (ac)² + 2abcd + (bd)² ↔ (ad)² + (bc)² ≥ 2abcd ↔ (ad)² - 2abcd + (bc)² ≥ 0 ↔ (ad - bc)² ≥ 0
• Dấu " = " xảy ra khi {\displaystyle {\frac {a}{c}}={\frac {b}{d}}}

cosi nhé

\(B=3\sqrt{2}-\sqrt{13+30\sqrt{2+\sqrt{\left(2\sqrt{2}+1\right)^2}}}\)

\(B=3\sqrt{2}-\sqrt{13+30\sqrt{2+2\sqrt{2}+1}}\)

\(B=3\sqrt{2}-\sqrt{13+30\sqrt{3+2\sqrt{2}}}\)

\(B=3\sqrt{2}-\sqrt{13+30\sqrt{\left(\sqrt{2}+1\right)^2}}\)

\(B=3\sqrt{2}-\sqrt{13+30\left(\sqrt{2+1}\right)}\)

\(B=3\sqrt{2}-\sqrt{13+30\sqrt{2}+30}\)

\(B=3\sqrt{2}-\sqrt{43+30\sqrt{2}}\)

\(B=3\sqrt{2}-\sqrt{\left(3\sqrt{2}+5\right)^2}\)

\(B=3\sqrt{2}-3\sqrt{2}-5\)

\(B=-5\)

vậy \(B=-5\)

\(B=3\sqrt{2}-\sqrt{13+30\sqrt{2+\sqrt{9+4\sqrt{2}}}}\\ \)

\(=3\sqrt{2}-\sqrt{13+30\sqrt{2+\sqrt{\left(2\sqrt{2}\right)^2+2.2\sqrt{2}+1^2}}}\)

\(=3\sqrt{2}-\sqrt{13+30\sqrt{2+2\sqrt{2}+1}}\)

\(=3\sqrt{2}-\sqrt{13+30\sqrt{\left(\sqrt{2}\right)^2+2\sqrt{2}+1}}\)

\(=3\sqrt{2}-\sqrt{13+30\left(\sqrt{2}+1\right)}\)

\(=3\sqrt{2}-\sqrt{13+30\sqrt{2}+30}\)

\(=3\sqrt{2}-\sqrt{43+30\sqrt{2}}\)

\(=3\sqrt{2}-\sqrt{\left(3\sqrt{2}\right)^2+2.5.3\sqrt{2}+5^2}\)

\(=3\sqrt{2}-3\sqrt{2}+5=5\)

rất chi tiết đó bạn