B1 : Tính
a) \(\sqrt{1,2.270}\) ; \(\sqrt{55.77.35}\)
b) (\(\sqrt{3}\)-\(\sqrt{2}\))\(^2\) ; (\(3\sqrt{2}-1\))\(\left(3\sqrt{2}+1\right)\) ; \(\left(\sqrt{6}+2\right)\left(\sqrt{3}-2\right)\)
c) \(\left(\sqrt{\dfrac{3}{2}}-\sqrt{\dfrac{2}{3}}\right)\) ; \(\left(\sqrt{\dfrac{8}{3}}-\sqrt{24}+\sqrt{\dfrac{50}{3}}\right).\sqrt{6}\)
B2 : Thực hành phép tính :
a) \(\sqrt{\dfrac{1}{8}}.\sqrt{2}.\sqrt{125}.\sqrt{\dfrac{1}{5}}\) ; \(\sqrt{\left(\sqrt{2}-1\right)}.\sqrt{\left(\sqrt{2}+1\right)}\)
b) \(\sqrt{\left(\sqrt{2}-3\right)^2}\cdot\sqrt{11\cdot6\sqrt{2}}\) ; \(\sqrt{\left(\sqrt{3}-3\right)^2}\cdot\sqrt{\dfrac{1}{3-\sqrt{3}}}\)
b1 : Phân tích đan thức thành nhân tử
a) x - 5 ( vs x > 0 )
b) 5 - 7\(x^2\) (vs x > 0)
b2 :Rút gọn bt
a) x - 4 + \(\sqrt{x^2-8x+16}\) vs x < 4
b) \(\sqrt{\left(\sqrt{x}-\sqrt{y}\right)^2\left(\sqrt{x}+\sqrt{y}\right)^2}vs0\le x\le y\)
B1: bt sau đây xác định vs gt nào của x
a)\(\sqrt{\dfrac{4}{2x+3}}\)
b)\(\sqrt{x\left(x+2\right)}\)
c)\(\sqrt{\dfrac{2x-1}{2-x}}\)
B2: tính
a)\(\sqrt{\left(\sqrt{3}-2\right)^2}\) b)\(\sqrt{4-2\sqrt{3}}\) c)\(\sqrt{3+2\sqrt{2}}\) d)\(\sqrt{9-4\sqrt{5}}\)
B3: Tìm x bik:
a) \(\sqrt{25-20x+4x^2}+2x=5\) b)\(\sqrt{x^2+\dfrac{1}{2}x+\dfrac{1}{16}}=\dfrac{1}{4}-x\) c)\(\sqrt{x-2\sqrt{x-1}}=2\)