a) \(\left(2x-3\right)^2=36\)
\(\left(2x-3\right)^2=6^2\)
\(2x-3=6\)
\(2x=9\)
\(x=4,5\)
b) \(\left(2x-1\right)^5=243\)
\(\left(2x-1\right)^5=3^5\)
\(2x-1=3\)
\(2x=4\)
\(x=2\)
Bài 1 thực hiện phép tính
a)\(\frac{45}{19}-\left(\frac{1}{2}+\left(\frac{1}{3}+\left(\frac{1}{4}\right)^{-1}\right)^{-1}\right)^{-1}.\)
b) \(\frac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^{10}.6^{19}-7.2^{29}.27^6}.\)
Bài 2. tìm x, biết:
a) 2(x-1) - 3(2x+2) - 4(2x+3) =16
b) \(3\frac{1}{2}:\left|2x-1\right|=\frac{21}{22}\)
c) |x2+|x-1|| = x2+2
Bài 3. Chứng minh rằng số có dạng abcabc luôn chia hết cho 11
Bài 4.tính:
a) A = \(\left(\frac{0,4-\frac{2}{9}+\frac{2}{11}}{1,4-\frac{7}{9}+\frac{7}{11}}-\frac{\frac{1}{3}-0,25+\frac{1}{5}}{1\frac{1}{6}-0,875+0,7}\right):\frac{2012}{2013}\)
b) B =\(4.\left(-\frac{1}{2}\right)^2-2.\left(-\frac{1}{2}\right)^2+3.\left(-\frac{1}{2}\right)+1\)
c) C =\(\frac{1}{2}:\left(-1\frac{1}{2}\right):1\frac{1}{3}:\left(-1\frac{1}{4}\right):1\frac{1}{5}:\left(-1\frac{1}{6}\right):...:\left(-1\frac{1}{100}\right)\)
d) D =\(\frac{4^6.9^5+6^9.120}{-8^4.3^{12}+6^{11}}\)
1.Tính
A= $$
B=\(1-\frac{1}{1-2^{-1}}+\frac{1}{1+\frac{1}{2^{-1}}}\)
2. Tìm x, biết:
a) \(\left(2x-3\right)^2=36\)
b) \(\left(2x-1\right)^5=243\)
c) \(\left(7x+2\right)^{-1}=3^{-2}\)
d) \(\left(2x-5\right)^{2000}+\left(3y+4\right)^{2002}\le0\)
\(^{\left(\frac{5^4-5^3}{125^4}\right)^3}\)
\(\frac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
\(\frac{\left(-0,7\right)^2.\left(-5\right)^3}{\left(-2\frac{1}{3}\right)^3.\left(1\frac{1}{2}\right)^4.\left(-1\right)^5}\)
tìm x,y biết:
a)\(\left(2x-5\right)^{2000}+\left(3y+4\right)^{2002}\le0\)
b)\(x=6:\frac{1}{3}-0,8:\frac{1,5}{\frac{3}{2}.0,4.\frac{50}{1:\frac{1}{2}}}+\frac{1}{4}+\frac{1+\frac{1}{2}.\frac{1}{0,25}}{6-\frac{46}{1+2,2.10}}\)
c)\(y=77^{-1}.7^4.11^2.\left(1.11\right)^4.\left(7^2\right)^{-8}.\left(7^{-8}\right)^{-3}.\frac{1}{\left(-11\right)^{-3}}\)
1) Tinh gia tri cua bieu thuc:
A=\(\frac{\left(1+2+...+100\right)\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{4}-\frac{1}{5}\right)\left(2,4.42-21.4,8\right)}{1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{100}}\)
B=\(\frac{4^6.9^5+6^9.120}{-8^4.3^{12}+6^{11}}\)
\(\frac{20^5.5^{10}}{100^5}.\frac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
\(\left(\frac{4}{9}+\frac{1}{3}\right)^2+\left(\frac{3}{4}\right)^3:\left(\frac{3}{4}\right)^2:\left(\frac{-2}{3}\right)^3\)
Tìm x và y biết:
d)\(-1\frac{2}{3}-\left(\left|2x\right|+\frac{5}{6}\right)=\)\(-2\)e)\(\left(-\frac{1}{2}+\frac{1}{3}\right):\left|1-2x\right|-1\frac{1}{4}:\left(-\frac{5}{8}\right).\left(-\frac{1}{2}\right)^2=\frac{1}{3}\)
c)\(\left|2x-1\right|+\left|2y+1\right|+\left|2x-y\right|=0\)b)\(\left|2x-1\right|=2x-1\)
a)\(\left|x-3\right|=x+4\)
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, \(\frac{5.\left(3.7^{15}-19.7^{14}\right)}{7^{16}+3.7^{15}}\)
Câu 1:(2^-1+3^-1):(2^-1-3^-1)+(2^-1.2^0):2^3
Câu 2: \(\left(-\frac{1}{3}\right)-\left(-\frac{6}{7}\right)^0+\left(\frac{1}{2}\right)^2:2\)
Câu 3: \(\frac{4^6.9^5+6^9.120}{-8^4.3^{12}-6^{11}}\)
Câu 4: \(\frac{1}{1-\frac{1}{1-2^{-1}}}+\frac{1}{1+\frac{1}{1+2^{-1}}}\)
