Rút gọn
\(A=\frac{a^2.a^7.b^2.c^8}{a^5.b^3.\left(-c\right)^4}\)
B=\(\left(\frac{3}{7}\right)^{5.}\frac{\left(25\right)^4.7^5}{15^4.20^2}\)
\(B=\left(\frac{3}{7}\right)^5.\frac{\left(25\right)^4.7^5}{15^4.20^2}\)
\(B=\left(\frac{3}{7}\right)^5.\frac{5^8.7^5}{3^4.5^4.2^4.5^2}\)
\(B=\frac{3^5.5^8.7^5}{3^4.5^6.2^4.7^5}\)
\(B=\frac{3.5^2}{2^4}\)
\(B=\frac{75}{16}\)
a, \(\left(7+\frac{7}{5}-\frac{2}{3}\right)-\left(4+\frac{4}{5}+\frac{3}{8}\right)+\left(3-\frac{3}{5}+\frac{2}{3}+\frac{3}{8}\right)\)
b.\(-\frac{13}{25}.\frac{5}{32}.\left(\frac{25}{-13}\right).\left(-64\right)\)
c.\(\frac{7}{80}:\left(-1\frac{3}{4}\right)-\frac{2}{9}:\left(8-\frac{8}{3}\right)-\left(-\frac{5}{24}\right)\left(-\frac{10}{3}+2\frac{8}{15}\right)\)
thực hiện phép tính rồi rút gọn
A=\(\left(\frac{4}{9}+\frac{5}{6}\right):\left(\frac{7}{8}-\frac{7}{12}\right)\)
B=\(\frac{3}{4}.\frac{8}{9}.\frac{15}{16}...\frac{9999}{10000}\)
C=\(\left[3-\frac{1}{5}+\frac{3}{10}\right]:\left(2+\frac{1}{4}-\frac{3}{5}\right)\)
\(a,\left(\frac{3}{7}+\frac{1}{2}\right)^2\)
\(b,\left(\frac{3}{4}-\frac{5}{6}\right)^2\)
\(c,\frac{5^4.20^4}{25^5.4^5}\)
Bài làm
\(a,\left(\frac{3}{7}+\frac{1}{2}\right)^2\)
\(=\left(\frac{3}{7}\right)^2+\left(\frac{1}{2}\right)^2\)
\(=\frac{9}{49}+\frac{1}{4}\)
\(=\frac{36}{196}+\frac{49}{196}\)
\(=\frac{85}{196}\)
\(b,\left(\frac{3}{4}-\frac{5}{6}\right)^2\)
\(=\left(-\frac{1}{12}\right)^2\)
\(=\frac{1}{144}\)
\(c,\frac{5^4.20^4}{25^5.4^5}\)
\(=\frac{5^4.\left(5.4\right)^4}{\left(5.5\right)^5.4^5}\)
\(=\frac{5^4.5^4.4^4}{5^5.5^5.4^5}\)
\(=\frac{1}{5.5.4}\)
\(=\frac{1}{100}\)
~ Check đúng cho minh nha. ~
# Học tốt #
\(a,\left(\frac{3}{7}+\frac{1}{2}\right)^2\)
\(< =>\left(\frac{6}{14}+\frac{7}{14}\right)^2\)
\(< =>\left(\frac{13}{14}\right)^2\)
\(< =>\frac{169}{196}\)
\(b,\left(\frac{3}{4}-\frac{5}{6}\right)^2\)
\(< =>\left(\frac{9}{12}-\frac{10}{12}\right)^2\)
\(< =>\left(\frac{-1}{12}\right)^2\)
\(< =>\frac{-1}{144}\)
\(c,\frac{5^4\cdot20^4}{25^5\cdot4^5}\)
\(< =>\frac{25^2\cdot\left(4\right)^4\cdot\left(5\right)^4}{25^5\cdot4^5}\)
\(< =>\frac{1\cdot1\cdot\left(5\right)^4}{25^3\cdot4}\)
\(< =>\frac{1\cdot25^2}{25^3\cdot4}\)
\(< =>\frac{1}{25\cdot4}\)
\(< =>\frac{1}{100}\)
a,(3/7)^2+2.3/7.1/2+(1/2)^2
=9/49+3/7+1/4
=169/196
b,(3/4)^2-2.3/4.5/6+(5/6)^2
=9/16-5/4+25/36
=1/144
Rút gọn các biểu thức sau :
a) \(A=\left(0,04\right)^{-1,5}-\left(0,125\right)^{\frac{-2}{3}}\)
b) \(B=\left(6^{\frac{-2}{7}}\right)^{-7}-\left[\left(\left(0,2\right)^{0,75}\right)^{-4}\right]\)
c) \(C=\frac{a^{\sqrt{5}+3}.a^{\sqrt{5}\left(\sqrt{5}-1\right)}}{\left(a^{2\sqrt{2}-1}\right)^{2\sqrt{2}+1}}\)
d) \(D=\left(a^{\frac{1}{2}}-b^{\frac{1}{2}}\right)^2:\left(b-2b\sqrt{\frac{b}{a}}+\frac{b^2}{a}\right)\left(a,b>0\right)\)
a) \(A=\left[\left(\frac{1}{5}\right)^2\right]^{\frac{-3}{2}}-\left[2^{-3}\right]^{\frac{-2}{3}}=5^3-2^2=121\)
b) \(B=6^2+\left[\left(\frac{1}{5}\right)^{\frac{3}{4}}\right]^{-4}=6^2+5^3=161\)
c) \(C=\frac{a^{\sqrt{5}+3}.a^{\sqrt{5}\left(\sqrt{5}-1\right)}}{\left(a^{2\sqrt{2}-1}\right)^{2\sqrt{2}+1}}=\frac{a^{\sqrt{5}+3}.a^{5-\sqrt{5}}}{a^{\left(2\sqrt{2}\right)^2-1^2}}\)
\(=\frac{a^{\sqrt{5}+3+5-\sqrt{5}}}{a^{8-1}}=\frac{a^8}{a^7}=a\)
d) \(D=\left(a^{\frac{1}{2}}-b^{\frac{1}{2}}\right)^2:\left(b-2b\sqrt{\frac{b}{a}}+\frac{b^2}{a}\right)\)
\(=\left(\sqrt{a}-\sqrt{b}\right)^2:b\left[1-2\sqrt{\frac{b}{a}}+\left(\sqrt{\frac{b}{a}}\right)^2\right]\)
\(=\left(\sqrt{a}-\sqrt{b}\right)^2:b\left(1-\sqrt{b}a\right)^2\)
Bài 1: Tính giá trị các biểu thức sau
a, \(\left[2^{-3}-\left(\frac{3}{4}\right)^{-4}.\left(-\frac{1}{2}\right)^2\right]:\left[5-3.\left(\frac{4}{15}\right)^0\right]^{-2}\)
b, \(\frac{5^5.20^3-5^4.20^3+5^7.4^5}{\left(20+5\right)^3.4^5}\)
c, \(\frac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
d, \(\frac{5.\left(3.7^{15}-19.7^{14}\right)}{7^{16}+3.7^{15}}\)
Bài 1: Tính giá trị các biểu thức sau
a,\(\left[2^{-3}-\left(\frac{3}{4}\right)^{-4}.\left(-\frac{1}{2}\right)^2\right]:\left[5-3\left(\frac{4}{15}\right)^0\right]^{-2}\)
b, \(\frac{2^3+3.2^6-4^3}{2^3+3^2}\)
c, \(\frac{5^5.20^3-5^4.20^3+5^7.4^5}{\left(20+5\right)^3.4^5}\)
d, \(\frac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
e, \(\frac{5.\left(3.7^{15}-19.7^{14}\right)}{7^{16}+3.7^{15}}\)
f, \(\frac{3^3.\left(0,5\right)^5}{\left(1,5\right)^4}\)
Mk cần gấp
f) \(\frac{3^3.\left(0,5\right)^5}{\left(1,5\right)^4}=\frac{3^3.\left(0,5\right)^5}{\left[3.\left(0,5\right)\right]^4}=\frac{3^3.\left(0,5\right)^5}{3^4.\left(0,5\right)^4}=\frac{0,5}{3}=\frac{1}{6}\)
b) \(\frac{2^3+3.2^6-4^3}{2^3+3^2}=\frac{2^3.\left(1+3.2^3-2^3\right)}{2^3+3^2}=\frac{2^3.17}{17}=2^3=8\)
Các phần còn lại tương tự, bạn tự làm nhé !
(*) Lưu ý ở những bài rút gọn có chứa lũy thừa thì bạn đưa số đó về số nguyên tố rồi thực hiện như bình thường .
VD : \(4^3=\left(2^2\right)^3=2^6\) ( đưa về số nguyên tố là 2 )
\(6^3=\left(2.3\right)^3=2^3.3^3\) ( đưa về tích hai số nguyên tố )
Rút gọn
a)\(\frac{25^{5^{ }}.5^{10}}{100^5}.\frac{4^6.9^5+6^9.120}{8^4.3^{12^{ }}-6^{11}}\)
b)\(\left(\frac{4}{9}+\frac{1}{3}\right)^2+\left(\frac{3}{4}\right)^2:\left(\frac{3}{4}\right)^2:\left(-\frac{2}{3}\right)^3\)
c) (273 : 33) : \(\left[\left(\frac{3}{5}\right)^{15}:\left(\frac{9}{25}\right)^5\right]\)
CÁC BẠN GIÚP MIH VỚI
Bài 1: Thực hiện phép tính bằng cách hợp lí < nếu có thể >
a, \(\left(-1,5\right).\left(1+\frac{2}{3}\right)+1,4.\frac{15}{49}-\left(\frac{4}{5}+\frac{2}{3}\right):2\frac{1}{5}\)
b, \(\frac{7}{5}+\frac{4}{5}\left(\frac{5}{8}-\frac{7}{4}\right)+2014^0\)
c, \(1\frac{3}{25}+\frac{17}{19}-\frac{3}{25}+0,9+\frac{2}{19}\)
d, \(-\frac{5}{9}.\frac{6}{13}+\frac{-5}{9}.\frac{7}{23}+\frac{5}{23}:\frac{9}{7}\)
Bài 2: Tìm x, biết
a, 20%x + 0,4x = 4,5
b, \(\left(3\frac{1}{2}-2\left|x-1\right|\right).2\frac{2}{3}=5\frac{1}{3}\)
HELP MEEEEE
Bài 1:
d)
= \(\frac{-5}{9}\left(\frac{6}{13}+\frac{7}{13}\right)+\frac{5}{23}.\frac{7}{9}\)
= \(\frac{-5}{9}.1+\frac{35}{207}\)
= \(\frac{-80}{207}\)
Bài 2:
a) 20%x + 0,4x = 4,5
x( 20% + 0,4 ) = 4,5
x. 0,6 = 4,5
x = 4,5 : 0,6
x = 7,5