\(=1+\dfrac{1}{2}+2+\dfrac{1}{4}+3+\dfrac{1}{8}+...+7+\dfrac{1}{128}\)

\(=\left(1+2+...+7\right)+\left(\dfrac{1}{2}+\dfrac{1}{4}+\dfrac{1}{8}+...+\dfrac{1}{128}\right)\)

\(=28+\left(1-\dfrac{1}{1}-+\dfrac{1}{2}-\dfrac{1}{4}+...+\dfrac{1}{64}-\dfrac{1}{128}\right)\)

\(=28+\left(1-\dfrac{1}{128}\right)\)

\(=28+\dfrac{127}{128}\)

\(=\dfrac{3711}{128}\)

1) 125.(-24) + 24.225.

\(=24\left(-125+225\right)=24.100=2400.\)

2) 512.(2 – 128) – 128. (-512).

\(=512\left(2-128+128\right)=512.2=1024.\)

1) (-12).46-12.54

=12.(-46)-12.54

=12.(-46-54)

=12.(-100)=(-1200)

10) 17.(-25)+25.21

= (-17).25+25.21

=25.(-17+21)

=25.4=100

( Mik đọc lướt qua thì thấy hai bài này dễ nên làm, chứ mấy bài kia chưa suy nghĩ gì, bạn tự làm nốt nhé!)

2: \(=\left(3784-3785\right)+\left(23-15\right)=\left(-1\right)+8=7\)

3: \(=-8\cdot25\cdot2\cdot4\cdot5\cdot125\)

\(=-8\cdot125\cdot25\cdot4\cdot2\cdot5=-1000\cdot100\cdot10=-1000000\)

4: \(=19\left(25+9\cdot5+30\right)=19\cdot100=1900\)

5: \(=-50+19+143+79-25-48\)

\(=\left(-50-25+79\right)+143+19-48\)

=54+143-29

=143+25=168

6: \(=-25\cdot75+25\cdot45-75\cdot45+75\cdot25\)

\(=45\left(25-75\right)=45\cdot\left(-50\right)=-2250\)

7: \(=-54\cdot\left(-9\right)+35\cdot\left(-20\right)\)

\(=486-700=-214\)

8: \(=187-23-20+180=164+160=324\)

9: \(=512\left(2-128+128\right)=512\cdot2=1024\)

ai trả lời nhanh và đúng nhất tớ k cho

p=91,q tu tinh di

số số hạng của dãy số P là : (25-1):4+1=7(số)

tổng dãy số P là : (25+1)*7:2=91

số số hạng của dãy số Q là :

(128-1):1+1=128(số)

tổng dãy số Q là:(128+1)*128:2=8256

k mk nha

yeu cau la gi vay ban

tính P x Q

1/\(\left(-12\right)\cdot46-12\cdot54=\left(-12\right)\cdot46+\left(-12\right)\cdot54\)

\(=\left(-12\right)\cdot\left(46+54\right)=\left(-12\right)\cdot100=-1200\)

2/\(3784+23-3785-15=3785+22-3785-15\)

\(=22-15=7\)

3/\(\left(-8\right)\cdot25\cdot\left(-2\right)\cdot4\cdot\left(-5\right)\cdot125\)

\(=\left[\left(-8\right)\cdot125\right]\cdot\left[25\cdot4\right]\cdot\left[\left(-5\right)\cdot\left(-2\right)\right]\)

\(=\left(-1000\right)\cdot100\cdot10=-1000000\)

4/\(19\cdot25+9\cdot95+19\cdot30=19\cdot\left(25+30\right)+9\cdot95\)

\(=19\cdot55+9\cdot95=95\cdot11+9\cdot95=95\cdot\left(11+9\right)=20\cdot95=1900\)

5/\(\left(-50+19+143\right)-\left(-79+25+48\right)\)

\(=\left(-50\right)+19+143+79-25-48\)

\(=118\)

6/\(\left(-25\right)\cdot\left(75-45\right)-75\cdot\left(45-25\right)\)

\(=\left(-25\right)\cdot30+\left(-25\right)\cdot3\cdot20\)

\(=\left(-25\right)\cdot\left(30+60\right)=\left(-25\right)\cdot90=-2250\)

7/\(\left(-37-17\right)\cdot\left(-9\right)+35\left(-9-11\right)\)

\(=\left(-54\right)\cdot\left(-9\right)+35\cdot\left(-20\right)\)

\(=486+\left(-700\right)=-214\)

8/\(\left(187-23\right)-\left(20-180\right)\)

\(=187-23-20+180=324\)

9/\(512\cdot2-128\cdot\left(-512\right)\)

\(=512\cdot2+128\cdot512=512\cdot\left(2+128\right)\)

\(=512\cdot130=66560\)

10/\(17\cdot\left(-25\right)+25\cdot21\)

\(=17\cdot\left(-25\right)-\left(-25\right)\cdot21=\left(-25\right)\cdot\left(17-21\right)\)

\(=\left(-25\right)\cdot\left(-4\right)=100\)

Chúc bạn học tốt.

P=1+5+9+..+25

so so hang=(25-1)/4+1=7

P=(1+25)*7/2=13.7

Q=2^0+2^1+2^2+...+2^7

2Q=2^1+2^2+..+2^8

2Q-Q=Q=(2^8-2^0)/2

Q=2^8-1

a) \(\left(-25\right).8.\left(-4\right).\left(-125\right).3\)

\(=\text{ }\left[\left(-25\right).\left(-4\right)\right].\text{ }\left[8.\left(-125\right)\right].3\)

\(=100.\left(-1000\right).3\)

\(=-100000.3\)

\(=-300000\)

b) \(27.\left(-17\right)+17.\left(-73\right)\)

\(=\left(-27\right).17+17.\left(-73\right)\)

\(=17\left[\left(-27\right).\left(-73\right)\right]\)

\(=17.\left(-100\right)\)

\(=-1700\)

c) \(512\left(2-128\right)-128\left(-512\right)\)

\(=512.2-512.128-128\left(-512\right)\)

\(=512.2-128\left[512+\left(-512\right)\right]\)

\(=1024-128.0\)

\(=1024-0\)

\(=1024\)

a, (-25).8.(-4).(-125).3

= (-25).(-8).(-4).(-125).(-3)

= {(-25).(-4)}.{(-8).(-125)}.(-3)

= 100.1000.(-3)

= 100000.(-3)

= -300000

b, 27.(-17)+17.(-73)

= 27.17+17.73

= 27.(17+73)

=27.90

=2430

c, 512.(2-128)-128.(-512)

= 512.(-2) - 512.128 - (-128).512

= { 512.{(-2)-128-(-128)}

= 512.{(-2).256}

=512.(-512)

= -262144

à cho mik xin lỗi câu c nha