tính nhanh :
\(\dfrac{-1}{6}+\dfrac{5}{-12}+\dfrac{7}{12}\)
\(\dfrac{4}{45}+\dfrac{-1}{45}+\dfrac{7}{45}+\dfrac{4}{45}+\dfrac{-2}{45}+\dfrac{-1}{5}\)
a: \(=\dfrac{-2}{12}-\dfrac{5}{12}+\dfrac{7}{12}=0\)
b: \(=\left(\dfrac{4}{45}-\dfrac{1}{45}+\dfrac{7}{45}+\dfrac{4}{45}-\dfrac{2}{45}-\dfrac{9}{45}\right)=\dfrac{3}{45}=\dfrac{1}{15}\)
45*2+45*7+45*2
\(45.2+45.7+45.2\)
\(=45.\left(2+7+2\right)\)
\(=45.11\)
\(=495\)
\(45.2+45.7+45.2\)
\(=45.\left(7+2+2\right)\)
\(=45.11\)
\(=495\)
\(45.2+45.7+45.2\)
\(=45.\left(2+7+2\right)\)
\(=45.11\)
\(=495\)
K mình nha leon
Mọi người cũng k mình nha!
(1+3+5+7+.......+97)*(45*3-45*2-45)=
\(\left(1+3+5+7+....+97\right)\cdot\left(45\cdot3-45\cdot2-45\right)\)
\(=\left(1+3+5+7+....+97\right)\cdot\left[45\cdot\left(3-2-1\right)\right]\)
\(=\left(1+3+5+7+....+97\right)\cdot\left(45\cdot0\right)\)
\(=\left(1+3+5+7+....+97\right).0\)
\(=0\)
\(\approx GOOD\)\(LUCK\approx\)
1+23++31++123+12+4+15+5+7+624+++857+8+854++5+4+2+4+6+4+++54+63542+513++8524+5+6+4+6+45+6+4++532+7+9863+4+6+37+++5463+45++6324+3+1++3+23+4+5+34+5+45++45+54+45++35+45+
phép tính như vậy và hỏi
nó chỉ đành cho mấy đứa ngu như mi thôi THV
bằng N
N là số tự nhiên
A = 5/18*23 + 1/23*24 + 7/24*31 + 2/31*33 + 4/33*37 + 1/38*45 + 7/38*45 + 9/45*54
26/15 : 19/45 - 7/15 : 19/45
= (26/15-7/15):19/45
=\(\dfrac{19}{15}:\dfrac{19}{45}\)
=\(\dfrac{19}{15}x\dfrac{45}{19}=\dfrac{45}{15}=3\)
= ( 26/15 - 7/15 ) : 19/45
= 19/15 : 19/15
=1
\(\dfrac{26}{15}:\dfrac{19}{45}-\dfrac{7}{15}:\dfrac{19}{45}\)
\(=\left(\dfrac{26}{15}-\dfrac{7}{15}\right):\dfrac{19}{45}\)
\(=\dfrac{19}{15}:\dfrac{19}{45}\)
\(=\dfrac{19}{15}\) x \(\dfrac{45}{19}\)
\(=\dfrac{855}{285}=3\)
7 giờ 45 phút 3 giờ 45 phút
Tìm x
\(\frac{3}{3+5}+\frac{3}{5+7}+\frac{3}{7+9}+...+\frac{3}{43+45}=\frac{x}{45}\)\(\frac{x}{45}\)
cho mình bỏ đi 1 phân số \(\frac{x}{45}\)ở cuối nhé
1+2+45+7+87877+87+8+7+87+5+45+4+24+542+4+4+54+5+45+454+5=?
bao nhiêu các bn
ai biết thì kết bn với tớ