117 - ( 69 ) + 15 + ( -25 ) - 117
1. Rút gọn
4- 1/23 - 56/39 - 25/77
--------------------------------
5/69 + 5/117 + 5/171
1. Rút gọn
4- 1/23 - 56/39 - 25/77
--------------------------------
5/69 + 5/117 + 5/171
\(\frac{4-\frac{1}{23}-\frac{56}{39}-\frac{25}{47}}{\frac{5}{69}+\frac{5}{117}+\frac{5}{141}}\)
B=\(\frac{4-\frac{1}{23}-\frac{56}{39}-\frac{25}{47}}{\frac{5}{69}+\frac{5}{117}+\frac{5}{141}}\)
Tính hợp lí :
\(B=\frac{4-\frac{1}{23}-\frac{56}{39}-\frac{25}{47}}{\frac{5}{69}+\frac{5}{117}+\frac{5}{141}}\)
1, Tính hợp lí:
A=\(\frac{4-\frac{1}{23}-\frac{56}{39}-\frac{25}{47}}{\frac{5}{69}+\frac{5}{117}+\frac{5}{141}}\)
\(\frac{4-\frac{3}{69}-\frac{168}{117}-\frac{75}{141}}{\frac{5}{69}+\frac{5}{117}+\frac{5}{141}}\)
=\(\frac{\frac{66}{69}-\frac{66}{117}-\frac{66}{141}}{\frac{5}{69}+\frac{5}{117}+\frac{5}{141}}\)
=\(\frac{66\left(\frac{1}{69}+\frac{1}{117}+\frac{1}{141}\right)}{5\left(\frac{1}{69}+\frac{1}{117}+\frac{1}{141}\right)}\)
=\(\frac{66}{5}\)
-117 -[-117-(-15)]
=-117-[-117+15]
=-117-[-(117-15)]
=-117-(-102)
=-117+102
=-(117-102)
=-15
k cho minh nha
Tìm x, biết rằng:
a) 5 8 x + 2 5 = 1 5
b) 5 7 : x + 11 7 = 18 7
c) 2 x 5 − 1 : − 5 = 1 7
a)
5 8 x + 2 5 = 1 5 5 8 x = 1 5 − 2 5 5 8 x = − 1 5 x = − 1 5 : 5 8 x = − 1 5 . 8 5 x = − 8 25
b)
5 7 : x + 11 7 = 18 7 5 7 : x = 18 7 − 11 7 5 7 : x = 1 x = 5 7 : 1 x = 5 7
c)
2 x 5 − 1 : − 5 = 1 7 2 x 5 − 1 = 1 7 . − 5 2 x 5 − 1 = − 5 7 2 x 5 = − 5 7 + 1 2 x 5 = 2 5 x = 2 5 : 2 5 x = 1
Tìm x, biết rằng:
a) 5 8 x + 2 5 = 1 5
b) 5 7 : x + 11 7 = 18 7
c) 2 x 5 − 1 : − 5 = 1 7
a)
5 8 x + 2 5 = 1 5 5 8 x = 1 5 − 2 5 5 8 x = − 1 5 x = − 1 5 : 5 8 x = − 1 5 . 8 5 x = − 8 25
b)
5 7 : x + 11 7 = 18 7 5 7 : x = 18 7 − 11 7 5 7 : x = 1 x = 5 7 : 1 x = 5 7
c)
2 x 5 − 1 : − 5 = 1 7 2 x 5 − 1 = 1 7 . − 5 2 x 5 − 1 = − 5 7 2 x 5 = − 5 7 + 1 2 x 5 = 2 5 x = 2 5 : 2 5 x = 1
a,\(\frac{5}{8}x+\frac{2}{5}=\frac{1}{5}\)
\(< =>\frac{5}{8}x=\frac{1}{5}-\frac{2}{5}\)
\(< =>\frac{5}{8}x=-\frac{1}{5}\)
\(< =>x=-\frac{1}{5}:\frac{5}{8}=-\frac{8}{25}\)
\(\frac{5}{7}:x+\frac{11}{7}=\frac{18}{7}\)
\(< =>\frac{5}{7}.\frac{1}{x}=\frac{18}{7}-\frac{11}{7}\)
\(< =>\frac{5}{7x}=\frac{7}{7}=1\)
\(< =>7x=5< =>x=\frac{5}{7}\)