(-2/5) nhân 4/15 cộng (-3/10) nhân 4/15
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
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
![](https://rs.olm.vn/images/avt/0.png?1311)
6 2/7 + 7 3/5 + 8 6/9 + 9 1/4 + 2/5 + 5/7 + 1/3 x 3/4 + 1967
= 44/7 + 38/5 + 78/9 + 37/4 + 2/5 + 5/7 + 1/3 + 1967
= ( 44/7 + 5/7 ) + ( 38/5 + 2/5 ) + ( 26/3 + 1/3 ) + ( 37/4 + 3/4 ) +1967
= 7 + 8 + 9 + 10 + 1967
= 15 + 9 + 10 + 1967
= 24 + 10 + 1967
= 34 + 1967
= 2001
![](https://rs.olm.vn/images/avt/0.png?1311)
a) \(\frac{10^4.81-16.15^2}{\left(-8\right)^4.3^{12}+6^{11}}=\frac{10^4.3^4-4^2.15^2}{8^4.3^{12}+6^{11}}=\frac{30^4-60^2}{2^{12}.3^{12}+6^{11}}=\frac{\left(30^2\right)^2-60^2}{6^{12}+6^{11}}\)
\(=\frac{900^2-60^2}{6^{11}.\left(6+1\right)}=\frac{60^2.\left(15^2-1\right)}{6^{11}.7}=\frac{60^2.224}{6^{11}.7}=\frac{2^9.3^2.5^2.7}{2^{11}.3^{11}.7}=\frac{5^2}{2^2.3^9}=\frac{25}{78732}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a: =35/17-18/17-9/5+4/5
=1-1=0
b: =-7/19(3/17+8/11-1)
=7/19*18/187=126/3553
c: =26/15-11/15-17/3-6/13
=1-6/13-17/3
=7/13-17/3=-200/39
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
dễ, nhưng phai giai dc câu nay 60% nhan x cong 2 phan 3 = 1 phan 3 nhan 6va 1 phan 3
![](https://rs.olm.vn/images/avt/0.png?1311)
157*(17-7)=......
(-37)*86 - (-37)*76=(-37)*(86-76)=.......
1975*(-115+15)=....
199*[(15-17)-(-17+5)]=........
17*[-84+(-16)]=.......
![](https://rs.olm.vn/images/avt/0.png?1311)
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/ \(\left(-37\right).86+37.76\)
\(=37.\left(-86\right)+37.76\)
\(=37.\left(-86+76\right)\)
\(=37.\left(-10\right)\)
\(=-370\)
![](https://rs.olm.vn/images/avt/0.png?1311)
khỏi chép đề nha
a\Câu 1:
200 : ( 15 - x ) = 15 + 5
200 : ( 15 - x ) = 20
15 - x = 200 : 20
15 - x = 10
x = 15 - 10
x = 5
Câu 2:
63 : ( x - 5 ) = 22 -1
63 : ( x - 5 ) = 21
x - 5 = 63 : 21
x - 5 = 3
x = 3 + 5
x = 8
Lời giải:
$\frac{-2}{5}.\frac{4}{15}+\frac{-3}{10}.\frac{4}{15}$
$=\frac{4}{15}(\frac{-2}{5}+\frac{-3}{10})$
$=\frac{4}{15}.\frac{-7}{10}=\frac{-14}{75}$
\(\left(-\dfrac{2}{5}\right)\times\dfrac{4}{15}+\left(-\dfrac{3}{10}\right)\times\dfrac{4}{15}\)
\(=\left[-\dfrac{2}{5}+\left(-\dfrac{3}{10}\right)\right]\times\dfrac{4}{15}\)
\(=\left(\dfrac{-7}{10}\right)\times\dfrac{4}{15}\)
\(=\dfrac{-14}{75}\)