Bài 1: Thực hiện phép tính:
a,\(\left(\frac{-3}{4}+\frac{2}{7}\right):\frac{2}{7}+\left(\frac{-1}{4}+\frac{5}{7}\right):\frac{2}{3}\)
b,\(\left(-\frac{1}{3}\right)^2\cdot\frac{4}{11}+\frac{7}{11}\cdot\left(-\frac{1}{3}\right)^2\)
c,...
Đọc tiếp
Bài 1: Thực hiện phép tính:
a,\(\left(\frac{-3}{4}+\frac{2}{7}\right):\frac{2}{7}+\left(\frac{-1}{4}+\frac{5}{7}\right):\frac{2}{3}\)
b,\(\left(-\frac{1}{3}\right)^2\cdot\frac{4}{11}+\frac{7}{11}\cdot\left(-\frac{1}{3}\right)^2\)
c, \(\left(-\frac{1}{7}\right)^0-2\frac{4}{9}\cdot\left(\frac{2}{3}\right)^2\)
d,\(\frac{2^7\cdot9^2}{3^3\cdot2^5}\)
e,\(\left(\frac{1}{3}-\frac{5}{6}\right)^2+\frac{5}{6}:2\)
f,\(\left(9\frac{2}{4}:5,2+3.4\cdot2\frac{7}{34}\right):\left(-1\frac{9}{16}\right)\)
g,\(\sqrt{25}-3\sqrt{\frac{4}{9}}\)
h,\(\left(-2\right)^2+\sqrt{36}-\sqrt{9}+\sqrt{25}\)
i,\(\left(-\frac{1}{2}\right)^4+\left|-\frac{2}{3}\right|-2007^0\)
k,\(\left(-2\right)^3+\frac{1}{2}:\frac{1}{8}-\sqrt{25}+\left|-64\right|\)
m,\(\left(-3\right)^2\cdot\frac{1}{3}-\sqrt{49}+\left(-5\right)^3:\sqrt{25}\)
n,\(\frac{\sqrt{3^2+\sqrt{39^2}}}{\sqrt{91^2}-\sqrt{\left(-7\right)^2}}\)
Bài này là bài của lớp 9 nha!! có chỗ nào ko hiểu ib
\(a,A=\sqrt{18}+\sqrt{50}-\frac{1}{2}\sqrt{98}.\)
\(=3\sqrt{2}+5\sqrt{2}-\frac{7}{2}\sqrt{2}\)
\(=\sqrt{2}\left(3+5-\frac{7}{2}\right)\)
\(=\frac{9}{2}\sqrt{2}\)
\(b,B=\left(2\sqrt{3}+7\right)\left(2\sqrt{3}-7\right)\)
\(=2^2\sqrt{3^2}-7^2\)
\(=12-49=-37\)
a )
\(A=\sqrt{18}+\sqrt{50}-\frac{1}{2}\sqrt{98}\)
\(A=3\sqrt{2}+5\sqrt{2}-\frac{7}{2}\sqrt{2}\)
\(A=(3+5-\frac{7}{2})\sqrt{2}\)
\(A=\frac{9}{2}\sqrt{2}=\frac{9\sqrt{2}}{2}\)
b)
\(B=\left(2\sqrt{3}+7\right)\left(2\sqrt{3}-7\right)=\left(2\sqrt{3}\right)^2-7^2=12-49=-37\)