các bạn giúp mình bài này đc ko, mình ko hiểu lắm
1. Tính:
a/ A= \(\sqrt{2}.\left(\sqrt{8}-\sqrt{32}+3\sqrt{18}\right)\)
b/ B= \(\left(3+\sqrt{5}\right).\left(\sqrt{10}-\sqrt{2}\right).\sqrt{3-\sqrt{5}}\)
2/ Phân tích thành nhân tử:
a/ \(ab+b\sqrt{a}+\sqrt{a}+1\left(a,b\ge0\right)\)
b/ \(a\sqrt{b}+b\sqrt{a}\)
c/ a - b
d/ \(a\sqrt{a}+b\sqrt{b}\)
Cảm ơn các bạn nhé ^^
2.
a) =\(\left(ab+\sqrt{a}\right)+\left(b\sqrt{a}+1\right)\)
=\(\sqrt{a}\left(b\sqrt{a}+1\right)+\left(b\sqrt{a}+1\right)\)
=\(\left(\sqrt{a}+1\right)\left(b\sqrt{a}+1\right)\)
b)\(=\sqrt{ab}\left(\sqrt{a}+\sqrt{b}\right)\)
c)=
2c) \(=\left(\sqrt{a}\right)^2-\left(\sqrt{b}\right)^2\)
=\(\left(\sqrt{a}+\sqrt{b}\right)\left(\sqrt{a}-\sqrt{b}\right)\)
d)=\(=\left(\sqrt{a}\right)^2\sqrt{a}+\left(\sqrt{b}\right)^2\sqrt{b}\)
\(\left(\sqrt{a}\right)^3+\left(\sqrt{b}\right)^3\)
=\(\left(\sqrt{a}+\sqrt{b}\right)\left(a-2\sqrt{ab}+b\right)\)
bài 1
\(A=\sqrt{2}.\sqrt{8}-\sqrt{2}\sqrt{32}+3.\sqrt{2}\sqrt{18}\)
\(A=4-8+3.6=-4+18=14\)
