Tính
a) \(\left(-25\right).\left(75-45\right)-75.\left(45-25\right)\)
b) \(\frac{18.12-48.15}{-3.270-3.30}\)
c) \(\frac{2^5.7+2^5}{2^5.5^2-2^5.3}\)
I.Rút gọn rồi quy đồng mẫu các phân số sau
a, \(\dfrac{25.9-25.17}{\left(-8\right).80-8.10}\) ; \(\dfrac{48.12-48.15}{\left(-3\right).270-3.30}\) VÀ \(\dfrac{2^5.3}{600}\)
B, \(\dfrac{2^5.7+25}{25.5^2-2^5.3}\) VÀ\(\dfrac{3^4.5-3^6}{3^4.13+3^4}\)
a: \(\dfrac{25\cdot9-25\cdot17}{-8\cdot80-8\cdot10}=\dfrac{25\cdot\left(-8\right)}{\left(-8\right)\cdot\left(80+10\right)}=\dfrac{25}{90}=\dfrac{5}{18}=\dfrac{250}{900}\)
\(\dfrac{48\cdot12-48\cdot15}{\left(-3\right)\cdot\left(270+30\right)}=\dfrac{48}{300}=\dfrac{8}{50}=\dfrac{144}{900}\)
\(\dfrac{2^5\cdot3}{600}=\dfrac{96}{600}=\dfrac{144}{900}\)
b: \(\dfrac{2^5\cdot7+25}{25\cdot5^2-2^5\cdot3}=\dfrac{32\cdot7+25}{25\cdot25-32\cdot3}=\dfrac{249}{529}=\dfrac{1743}{7\cdot529}\)
\(\dfrac{3^4\cdot5-3^6}{3^4\cdot13+3^4}=\dfrac{3^4\left(5-9\right)}{3^4\left(13+1\right)}=\dfrac{-4}{14}=\dfrac{-2}{7}=\dfrac{-1058}{7\cdot529}\)
Tìm x, biết
|x2-25|+|x2-100|=75
b,\(\left|\frac{x}{2}-2\right|\in Z;\left|\frac{x}{2}-2\right|< 2\)
c, \(\left|x-\frac{1}{3}\right|+\frac{4}{5}=\left|\left(-3,2\right)+\frac{2}{5}\right|\)
mai bn đăng lại nhé mk lm cho h đi ngủ
rút gọn rồi quy đồng mẫu các phân số
\(\frac{25.9-25.17}{-8.80-8.10}\) và \(\frac{48.12-48.15}{-3.270-3.30}\)
\(\frac{2^5.7+2^5}{2^5.5^2-2^5.3}\) và \(\frac{3^4.5-3^6}{3^4.13+3^4}\)
Thực hiện các phép tính
a) \(25\%-\frac{5}{4}+1\frac{5}{6}\)
b) \(75\%:2\frac{1}{5}-\left(0,5\right)^2.\left(-7\right)+2,5\left(7\frac{2}{3}-5\frac{2}{3}\right)\)
c) \(45:2\frac{4}{7}+50\%-1,25\)
d) \(350\%:\frac{105}{24}+4\frac{5}{6}:2-\left(0,5^2\right).30\%\)
e) \(4\frac{2}{5}.0,5-1\frac{3}{7}.14\%+\left(-0,8\right)\)
\(\frac{0.5=0,\left(3\right)-0,1\left(6\right)}{2,5+1,6-0,8\left(3\right)}\)
\(-1,53:\left(5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}\right)\)
\(\left(3\frac{1}{3}.1,9+9,5:4\frac{1}{3}\right).\left(\frac{62}{75}-\frac{4}{25}\right)\)
\(\frac{\left(81,624:4,8-4,505\right)^2+125.0,75}{\left\{\left[\left(0,44\right)^2:0,88+3,53\right]^2-\left(2,75\right)^2\right\}:0,52}\)
\(\frac{6^6+6^3.3^3+3^6}{_{-73}}\)
\(\frac{8^{20}+4^{20}}{4^{25}+64^5}\)
\(\frac{45^{10}.5^{20}}{75^{15}}\)
\(16\frac{3}{5}.-\frac{1}{3}-13\frac{3}{5}.\frac{-1}{3}+\frac{3}{4}\)
\(\left(1\frac{1}{2}-0,5\right):9-30^2+\frac{1}{3}-\frac{1}{6}\)
Làm nhanh giúp mk nha!!!!!!!!!!!!!!
c, \(\frac{45^{10}.5^{10}}{75^{10}}\)
d, \(\frac{\left(\frac{2}{5}\right)^7.5^7+\left(\frac{9}{4}\right)^3:\left(\frac{3}{16}\right)^3}{2^7.5^2+512}\)
#)Giải :
c) \(\frac{45^{10}.5^{10}}{75^{10}}=\frac{\left(15.3\right)^{10}.5^{10}}{\left(15.5^{10}\right)}=\frac{15^{10}.3^{10}.5^{10}}{15^{10}.5^{10}}=3^{10}\)
Rút gọn phân số
a.\(\frac{25.9-25.17}{-8.80-8.10}\)
b.\(\frac{48.12-48.15}{-3.270-3.30}\)
c.\(\frac{2^5.7+2^5}{2^5.5^2-2^5.3}\)
d, \(\frac{3^4.5-3^6}{3^4.13+3^4}\)
a) \(\frac{25.9-25.17}{-8.80-8.10}=\frac{25.\left(9-17\right)}{-8.\left(80+10\right)}=\frac{25.\left(-8\right)}{-8.90}=\frac{5}{18}\)
b) \(\frac{48.12-48.15}{-3.270-3.30}=\frac{48.\left(12-15\right)}{-3.\left(270+30\right)}=\frac{48.\left(-3\right)}{-3.300}=\frac{4}{25}\)
c) \(\frac{2^5.7+2^5}{2^5.5^2-2^5.3}=\frac{2^5.\left(7+1\right)}{2^5.\left(5^2-3\right)}=\frac{2^5.8}{2^5.\left(25-3\right)}=\frac{2^5.8}{2^5.22}=\frac{4}{11}\)
d) \(\frac{3^4.5-3^6}{3^4.13+3^4}=\frac{3^4.\left(5-3^2\right)}{3^4.\left(13+1\right)}=\frac{3^4.\left(5-9\right)}{3^4.14}=\frac{3^4.\left(-4\right)}{3^4.14}=\frac{-2}{7}\)
Nguyễn Lương Bảo Tiên tại sao
3^4 × 5 - 3^6 lại = 3^4 (5 - 3^2) vậy
phần d ý
Rút gọn các phân thức sau:
\(a)\frac{{5{\rm{x}} + 10}}{{25{{\rm{x}}^2} + 50}}\)
\(b)\frac{{45{\rm{x}}\left( {3 - x} \right)}}{{15{\rm{x}}{{\left( {x - 3} \right)}^2}}}\)
\(c)\frac{{{{\left( {{x^2} - 1} \right)}^2}}}{{\left( {x + 1} \right)\left( {{x^3} + 1} \right)}}\)
a) Ta có: \(P = \frac{{x + 1}}{{{x^2} - 1}} = \frac{{x + 1}}{{\left( {x - 1} \right)\left( {x + 1} \right)}} = \frac{1}{{x - 1}}\)
Suy ra: \(Q = \frac{1}{{x - 1}}\)
b) Thay x = 11 vào P ta được: \(P = \frac{{11 + 1}}{{{{11}^2} - 1}} = \frac{1}{{10}}\)
Thay x = 11 vào Q ta được: \(Q = \frac{1}{{11 - 1}} = \frac{1}{{10}}\)
Hai kết quả P = Q tại x = 11
Rút gọn các phân thức sau:
\(a)\frac{{5{\rm{x}} + 10}}{{25{{\rm{x}}^2} + 50}}\)
\(b)\frac{{45{\rm{x}}\left( {3 - x} \right)}}{{15{\rm{x}}{{\left( {x - 3} \right)}^2}}}\)
\(c)\frac{{{{\left( {{x^2} - 1} \right)}^2}}}{{\left( {x + 1} \right)\left( {{x^3} + 1} \right)}}\)
\(a)\frac{{5{\rm{x}} + 10}}{{25{{\rm{x}}^2} + 50}} = \frac{{5\left( {x + 2} \right)}}{{25\left( {{x^2} + 2} \right)}} = \frac{{x + 2}}{{5\left( {{x^2} + 2} \right)}}\)
\(b)\frac{{45{\rm{x}}\left( {3 - x} \right)}}{{15{\rm{x}}{{\left( {x - 3} \right)}^2}}} = \frac{{3\left( {3 - x} \right)}}{{{{\left( {x - 3} \right)}^2}}}\)
\(c)\frac{{{{\left( {{x^2} - 1} \right)}^2}}}{{\left( {x + 1} \right)\left( {{x^3} + 1} \right)}} = \frac{{\left( {{x^2} - 1} \right)\left( {{x^2} - 1} \right)}}{{\left( {x + 1} \right)\left( {x + 1} \right)\left( {{x^2} - x + 1} \right)}} = \frac{{\left( {x + 1} \right)\left( {x - 1} \right)\left( {x + 1} \right)\left( {x - 1} \right)}}{{\left( {x + 1} \right)\left( {x + 1} \right)\left( {{x^2} - x + 1} \right)}} = \frac{{{{\left( {x - 1} \right)}^2}}}{{{x^2} - x + 1}}\)