Câu 1
a)=\(8\sqrt{3}-10\sqrt{3}+15\sqrt{3}=13\sqrt{3}\)
b)=\(4\sqrt{x}+6\sqrt{x}-6\sqrt{x}=4\sqrt{x}\)
c)=\(21\sqrt{2}+8\sqrt{2}-28\sqrt{2}=\sqrt{2}\)
d)\(\Rightarrow\)\(8\sqrt{2\sqrt{3}}-\sqrt{5\sqrt{3}}-4\sqrt{5\sqrt{3}}\)
\(\Rightarrow\)\(8\sqrt{2\sqrt{3}}-5\sqrt{5\sqrt{3}}\)
câu 2
a)\(\Rightarrow4x=64\)\(\Rightarrow x=16\)
b)\(\Rightarrow9x\le36\)\(\Rightarrow x\le4\)
Câu 2:
a: Ta có: \(\sqrt{4x}=8\)
\(\Leftrightarrow4x=64\)
hay x=16
b: Ta có: \(\sqrt{9x}\le6\)
\(\Leftrightarrow9x\le36\)
\(\Leftrightarrow x\le4\)
Kết hợp ĐKXĐ, ta được: \(0\le x\le4\)
Câu 1:
a: Ta có: \(2\sqrt{48}-\sqrt{300}+3\sqrt{75}\)
\(=8\sqrt{3}-10\sqrt{3}+15\sqrt{3}\)
\(=13\sqrt{3}\)
b: Ta có: \(\sqrt{16x}+2\sqrt{9x}-3\sqrt{4x}\)
\(=4\sqrt{x}+6\sqrt{x}-6\sqrt{x}\)
\(=4\sqrt{x}\)
c: Ta có: \(3\sqrt{98}+4\sqrt{8}-7\sqrt{32}\)
\(=21\sqrt{2}+8\sqrt{2}-28\sqrt{2}\)
\(=\sqrt{2}\)
