\(4^2\cdot120-4^3\cdot17+4^2\cdot34\)

\(=4^2\left(120-4\cdot17+34\right)\)

\(=16\left(120-68+34\right)\)

\(=16\cdot86=1088\)

\(7^3\cdot9+3^2\cdot7^4-45\cdot539\)

\(=7^3\cdot9+9\cdot7^4-45\cdot7^2\cdot11\)

\(=7^2\left(7\cdot9+9\cdot7^2-45\cdot11\right)\)

\(=49\left(63+9\cdot49-495\right)\)

\(=49\left(63+441-495\right)\)

\(=49\cdot9=441\)

\(5\cdot10^4+4\cdot10^3+6\cdot10^2+5\cdot10+9\)

\(=10\left(5\cdot10^3+4\cdot10^2+10\cdot6\right)+9\)

\(=10\left(5\cdot1000+4\cdot100+60\right)+9\)

\(=10\left(5000+400+60\right)+9\)

\(=10\cdot5460+9=54600+9=54609\)

2.4^x - 1 = 128

=> 4^x - 1 = 64

=> x - 1 = 3

=> x = 4

b, 17.4^2 + 83.16 

= 17.16 + 83.16

= 16(17 + 83)

= 16.100

= 1600

c, a^5 . 10^10.a^15

= a^20.10^10

d, 3{65 - [5(4 + 2.3) - 15] : 7}

= 3{65 - [5(4 + 6) - 15] : 7}

= 3{65 - [5.10 - 15] : 7}

= 3{65 - [50 - 15] : 7}

= 3{65 - 35 : 7}

= 3{65 - 5}

= 3.60

= 180

Các bạn giúp mình với mình đang cần gấp lắm

\(\frac{7}{3}.9-\frac{9}{4}.5+\frac{11}{5}.6-\frac{13}{6}.7+\frac{15}{7}.8-\frac{17}{8}.9+\frac{19}{9}.10\)

\(=21-\frac{45}{4}+\frac{66}{5}-\frac{91}{6}+\frac{120}{7}-\frac{153}{8}+\frac{190}{9}\)

\(=26,91230159\)

Lớp mấy đó

\(a,2x-5+17=6\\ \Rightarrow2x=-6\\ \Rightarrow x=-3\\ b,\Leftrightarrow10-8+6x=-4\\ \Leftrightarrow6x=-6\Leftrightarrow x=-1\\ d,\Rightarrow-2x=-10\\ \Rightarrow x=5\)

câu c giống câu b nhó

1: =-3x5+2x5-7x5+7x4=-8x5+7x4=-40+28=-12

2: =-3x5+3x6-4x3+4x2=-9+8=-1

3: =17(-84-16)=-1700

4: =1975(-115+15)=-197500

5: =-145x13+145x57+57x10-57x145=-1315

1/ \(5\left(-3+2\right)-7\left(5-4\right)\)

\(=5.\left(-3\right)+5.2-7.5-7.\left(-4\right)\)

\(=-15+10-35+28\)

\(=-5-7\)

\(=-12\)

2/ \(3.\left(-5+6\right)-4.\left(3-2\right)\)

\(=3.\left(-5\right)+3.6-4.3-4.\left(-2\right)\)

\(=-15+18-12+8\)

\(=3-4\)

\(=-1\)

3/ \(17.\left(-84\right)+17.\left(-16\right)\)

\(=17.\left(-84-16\right)\)

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

\(=-1700\)

4/ \(1975.\left(-115\right)+1975.15\)

\(=1975.\left(-115+15\right)\)

\(=1975.\left(-100\right)\)

\(=-197500\)

5/ \(-145.\left(13-57\right)+57.\left(10-145\right)\)

\(=-145.13-145.\left(-57\right)+57.10+57.\left(-145\right)\)

\(=-145.\left(-57+57\right)-145.13+57.10\)

\(=0-1885+570\)

\(=-1315\)

6/ \(157.17-157.7\)

\(=157.\left(17-7\right)\)

\(=157.10\)

\(=1570\)

7/ \(199.\left(15-17\right)-199.\left(-17+5\right)\)

\(=199.\left(-2\right)-199.\left(-12\right)\)

\(=199.\left(-2\right)+199.12\)

\(=199.\left(-2+12\right)\)

\(=199.10\)

\(=1990\)

8/ \(-39.\left(5-99\right)+99.\left(10-39\right)\)

\(=-39.5-39.\left(-99\right)+99.10+99.\left(-39\right)\)

\(=-39.\left(-99+99\right)-39.5+99.10\)

\(=0-195+990\)

\(=795\)

9/ \(-38.\left(25-4\right)+25.\left(-4+38\right)\)

\(=-38.25-38.\left(-4\right)+25.\left(-4\right)+25.38\)

\(=25.\left(-38+38\right)-4.\left(-38+25\right)\)

\(=0-4.\left(-13\right)\)

\(=52\)

10/ \(\left(-37\right).86+37.76\)

\(=37.\left(-86\right)+37.76\)

\(=37.\left(-86+76\right)\)

\(=37.\left(-10\right)\)

\(=-370\)

#maianhhappy

bài 1 tính giá trị biểu thức

( - 25 ) nhân ( -3 ) nhân x với x = 4

\(\left(-25\right).\left(-3\right).4\)

\(=\left(-25\right).4.\left(-3\right)\)

\(=-100.\left(-3\right)=300\)

( -1 ) nhân ( -4 ) nhân 5 nhân 8 nhân y với y =25

\(\left(-1\right).\left(-4\right).5.8.25\)

\(=4.5.8.25=4.25.5.8\)

\(=100.40=40000\)

( 2ab mũ 2 ) : c với a =4 ; b= -6 ; c =12

\(\left(2.4.\left(-6\right)\right)^2:12\)

\(=\left(-48\right)^2:12\)

\(=2304:12=192\)

[ ( -25 ) nhân ( - 27 ) nhân ( -x ) ] : y với x = 4 ; y = -9

\(\left[\left(-25\right).\left(-27\right).\left(-4\right)\right]:-9\)

\(=-2700:\left(-9\right)\)

\(=300\)

(a mũ 2 _ b mũ 2) : ( a + b ) nhân ( a _ b ) với a + 5 , b = -3

\(\left(5^2-\left(-3\right)^2\right):\left(5-3\right).\left(5+3\right)\)

\(=16:2.8\)

\(=8.8=64\)

bài 2 tìm x

( 2x _ 5 ) + 17 = 6

\(2x-5=-11\)

\(2x=-6\)

\(x=-3\)

10 _ 2 ( 4 _ 3x ) = - 4

\(2.\left(4-3x\right)=14\)

\(4-3x=7\)

\(3x=-3\)

\(x=-1\)

- 12 + 3 ( -x + 7 ) = -18

\(3\left(-x+7\right)=-6\)

\(-x+7=-2\)

\(-x=-9\)

\(x=9\)

24 : ( 3x _ 2 ) = -3

\(3x-2=-8\)

\(3x=-6\)

\(x=-2\)

- 45 : 5 nhân ( -3 _ 2x ) = 3

\(5.\left(-3-2x\right)=-15\)

\(-3-2x=-3\)

\(2x=0\)

\(x=0\)

Xem lại đề thiếu vế phải 

không có kết quả thì x là bao nhiêu mà chả được.

thiếu rồi