Tính.
\(\frac{49.\left(-113\right)+98.37-147}{7^3.\left(-9\right)}\)
Tính giá trị sau một cách hợp lí
M = \(\frac{\frac{1}{3}-\frac{1}{7}+\frac{1}{13}}{\frac{7}{3}-\frac{7}{7}+\frac{7}{13}}+\frac{\frac{2}{11}+\frac{4}{17}-\frac{6}{19}}{\frac{7}{11}-\frac{21}{19}+\frac{14}{17}}\)-19\(\frac{3}{7}\)
N = \(\frac{49.\left(-113\right)+98.37-147}{7^3.\left(-9\right)}\)
Đặt mỗi số số hạng của M là A;B
Ta quy đồng tử và mẫu của A bằng cách nhân cả tử và mẫu với 3.7.13;rồi dùng tính chất phân phối bỏ ngoặc ra.Tính toán bình thường.Khi đó A=1/7
Tương tự với B ta quy đồng lên với 11.17.19;bỏ ngoặc đi và tính bình thường ;B=2/7
=>M=1/7+2/7-136/7=3/7-136/7=-19
49.(-113)+98.37-147/7^3.(-9)
\(49.\left(-113\right)+98.37-(\dfrac{147}{7})^3.\left(-9\right)\)
\(=-5537+3626-\dfrac{147^3}{7^3}.\left(-9\right)\)
\(=-1911-\dfrac{3176523}{343}.\left(-9\right)\)
\(=-1911-9261.\left(-9\right)\)
\(=-1911-\left(-83349\right)\)
\(=81438\)
Tính giá trị biểu thức :
M=( 28 . 47 - 48 ) : 64
N=\(\frac{49.\left(-113\right)+94.37-147}{7^3.\left(-9\right)}\)
Tính
a) \(\left(\frac{3}{7}\right)^{21}:\left(\frac{9}{49}\right)^6\)
b) \(\left(-\frac{1}{3}\right)^{-1}-\left(-\frac{6}{7}\right)^0+\left(\frac{1}{2}\right):2\)
a) \(\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}^3\right)^6\)
\(=\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}\right)^{18}\)
\(=\left(\frac{3}{7}\right)^{21-18}\)
\(=\left(\frac{3}{7}\right)^3\)
\(=\frac{27}{343}\)
\(\left(\frac{3}{7}\right)^{21}:\left(\frac{9}{49}\right)^6\).Tính
\(\left(\frac{3}{7}\right)^{21}:\left(\frac{9}{49}\right)^6\)
\(=\left(\frac{3}{7}\right)^{21}:\left(\left(\frac{3}{7}\right)^2\right)^6=\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}\right)^{12}=\left(\frac{3}{7}\right)^{21-12}=\left(\frac{3}{7}\right)^9\)
\(\left(\frac{3}{7}\right)^{21}\div\left(\frac{9}{49}\right)^6=\left(\frac{3}{7}\right)^{21}\div\left[\left(\frac{3}{7}\right)^2\right]^6=\left(\frac{3}{7}\right)^{21}\div\left(\frac{3}{7}\right)^{12}=\left(\frac{3}{7}\right)^9\)
\(\left(\frac{3}{7}\right)^{21}\div\left(\frac{9}{49}\right)^6\)
\(=\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}\right)^{2^6}\)
\(=\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}\right)^{12}\)
\(=\left(\frac{3}{7}\right)^{21-12}\)
\(=\left(\frac{3}{7}\right)^9\)
Tính \(\left(\frac{3}{7}\right)^{20}:\left(\frac{9}{49}\right)^5\)
Bài làm
\(\left(\frac{3}{7}\right)^{20}:\left(\frac{9}{49}\right)^5\)
= \(\left(\frac{3}{7}\right)^{20}:\left(\frac{3}{7}^2\right)^5\)
= \(\left(\frac{3}{7}\right)^{20}:\left(\frac{3}{7}\right)^{10}\)
= \(\left(\frac{3}{7}\right)^{20-10}\)
= \(\left(\frac{3}{7}\right)^{10}\)
# Chúc bạn học tốt #
\(\left(\frac{3}{7}\right)^{20}=\left(\frac{9}{49}\right)^{10}\)
Rồi tự làm
Tính: \(\left(\frac{3}{7}\right)^{20}\div\left(\frac{9}{49}\right)^5\)
\(\left(\frac{3}{7}\right)^{20}\div\left(\frac{9}{49}\right)^5=\left(\frac{3}{7}\right)^{20}\div\left[\left(\frac{3}{7}\right)^2\right]^5\)
\(=\left(\frac{3}{7}\right)^{20}\div\left(\frac{3}{7}\right)^{10}=\left(\frac{3}{7}\right)^{10}\)
Tính
\(\left(\frac{3}{7}\right)^{21}:\left(\frac{9}{49}^6\right)\)
\(\left(\frac{3}{7}\right)^{21}\div\left(\frac{9}{49}\right)^6=\left(\frac{3}{7}\right)^{21}\div\left[\left(\frac{3}{7}\right)^2\right]^6=\left(\frac{3}{7}\right)^{21}\div\left(\frac{3}{7}\right)^{12}=\left(\frac{3}{7}\right)^9\)
Bn chỉnh lại đề đi sao lại tiếng anh hả vào toán đi ko được tick đâu
Tính:
\(\left(\frac{3}{7}\right)^{21}:\left(\frac{9}{49}\right)^6\)
(\(\frac{3}{7}\))21 : (\(\frac{9}{49}\))6
=(\(\frac{3}{7}\))21 : [(\(\frac{3}{7}\))2]6
= ( \(\frac{3}{7}\))21 : (\(\frac{3}{7}\))12
= ( \(\frac{3}{7}\))21-12 = (\(\frac{3}{7}\))9
\(\left(\frac{3}{7}\right)^{21}:\left(\frac{9}{49}\right)^6=\left(\frac{3}{7}\right)^{21}:\left(\left(\frac{3}{7}\right)^2\right)^6=\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}\right)^{2.6}=\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}\right)^{12}\)
\(=\left(\frac{3}{7}\right)^{21-12}=\left(\frac{3}{7}\right)^9\)
\(\left(\frac{3}{7}\right)^{21}:\left(\frac{9}{49}\right)^6\\ =\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}^2\right)^6\\ =\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}\right)^{2.6}\\ =\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}\right)^{12}\\ =\left(\frac{3}{7}\right)^{21-12}\\ =\left(\frac{3}{7}\right)^9\)