-75.57 + 75.34 - ( 57.34 - 57.75 )
-11.45 - (-11).25 - ( 29.3+29.17 )
-12.7 -72.(-12) - ( 25.55-25.43 )
5^11.7^12+7^11.5^11/5^12.7^12+9.5^11.7^11 =?
\(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}=\frac{5^{11}.7^{11}\left(7+1\right)}{5^{11}.7^{11}\left(5.7+9\right)}=\frac{8}{44}=\frac{2}{11}\)
5^11.7^12+7^11.5^11/5^12.7^12+9.5^11.7^11
5^11.7^12+5^11.7^11/5^12.7^11+9.5^11.7^11
\(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}=\frac{5^{11}.7^{11}\left(7+1\right)}{5^{11}.7^{11}\left(5.7+9\right)}=\frac{8}{44}=\frac{2}{11}\)
A=2^10.3^10-2^10.3^9/2^9.3^10
B=5^11.7^12+7^11.5^11/5^12.7^12+9.5^11.7^11
a, ( -4 ). 125 . ( -25). ( -11) . (-8)
b, ( -42 ). 25 . ( -25) .( - 5) . (-4)
c, ( -72) . ( 34 - 12) - 34. ( 12 - 72)
a, (-4) . 125 . (-25) . (-11) . (-8)
= [(-4) . (-25)] . {[125 . (-8)] . (-11)}
= 100 . 11000 = 1100000
b, (-42) . 25 . (-25) . (-5) . (-4)
= [(-42) . (-5)] . [25 . (-4)] . 25
= 210 . (-100) . 25
= -5025000
bài 1 tính
5.4^12.9^9-4.3^20.8^9/5.2^2^29.9^16-7.2^29.27^6/5^11.7^12+5^11.7^11/5^12.7^12+9.5^15.7^11
Tìm x biết :
4/x=8/6
3/x-5=-4/x+2
X/-2=-8/x
Rút gọn các phân số
2^4.5^2.11^2.7/2^3.5^3.7^2.11
2^10.3^10-2^10.3^9/2^9.3^10
5^11.7^12+5^12.7^11/5^12.7^12+9.5^11.7^11
1. Tìm x, biết:
a) \(\frac{4}{x}=\frac{8}{6}\). Ta có: \(\frac{8}{6}=\frac{8:2}{6:2}=\frac{4}{3}\Rightarrow x=3\)
b) \(\frac{3}{x-5}=\frac{4}{x+2}\). Ta có: \(5-2=3\)
\(\Rightarrow x=\left(3.5\right)+\left(4.2\right)+3=15+8+3=26\)
c) \(\frac{x}{-2}=\frac{-8}{x}\Rightarrow x=\left(-8\right):\left(-2\right)=4\)
2. Rút gọn
a) \(\frac{2^4.5^2.11^2.7}{2^3.5^3.7^2.11}\Leftrightarrow\frac{2^3.2^1.5^2.11.11.7}{2^3.5^2.5^1.7.7.11}\Leftrightarrow\frac{2^1.11}{5^1.7}=\frac{22}{35}\)
b) Tương tự
c) Tương tự
\(\frac{4}{x}=\frac{8}{6}\Rightarrow x=\frac{4.6}{8}=3\)
\(\frac{3}{x-5}=\frac{-4}{x+2}\Rightarrow3\left(x+2\right)=-4\left(x-5\right)\)
\(\Rightarrow3x+6=-4x+20\)
\(\Rightarrow3x+4x=20-6\)
\(\Rightarrow7x=14\)
\(\Rightarrow x=2\)
\(\frac{x}{-2}=\frac{-8}{x}\Rightarrow x^2=\left(-8\right)\left(-2\right)=16\Rightarrow x=\pm4\)
\(\frac{4}{x}=\frac{8}{6}\)
\(\Rightarrow4\cdot6=x\cdot8\)
\(\Rightarrow x=\frac{4\cdot6}{8}\)
\(\Rightarrow x=3\)
a)2^10.3^10:2^10.3^9/2^9.3^10.
b)5^11.7^12+5^11.7^11/5^12.7^12+9.5^11.7^11
câu 1 :23*75+25*12+180+25*11
câu 2; 25*46+75*84+25*72+34*75
*là nhân nhé