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-72(15-49) + 15 (-56 + 72)
= -72 . -34 + 15 . 16
= 2488 + 240
= 2728
-72(15-49)+15(-56+72) =-72.(-34)+15.16 =2448+240 = 2688 làm luôn :16.17.1.15625.1 =272.15625 =4250000
a)\(\left(x-32\right):16-13=48\)
\(\left(x-32\right):16=48+13\)
\(x+32=61.16\)
\(x+32=976\)
\(x=976-32\)
\(x=944\)
b) \(-2\left(2x-8\right)+\left(4-2x\right)=-72\)
\(-4x+16+4-2x=-72\)
\(-4x-2x=-72-16-4\)
\(-6x=-92\)
\(x=\frac{-92}{-6}=\frac{46}{3}\)
hok tốt!!
ko rảnh thì thôi đừng trả lời linh tinh chứ
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A=\(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{2014}{2015}.\frac{2015}{2016}\)
A=\(\frac{1.2.3.4...2015}{2.3.4...2016}=\frac{1}{2016}\)
Hok tốt
A = \(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{2015}\right).\left(1-\frac{1}{2016}\right)\)
= \(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}...\frac{2014}{2015}.\frac{2015}{2016}\)
= \(\frac{1}{2016}\)
Vậy ...
\(\hept{\begin{cases}3^2.\left(-2\right)^3=9.-8=-72\\-58\end{cases}}\) =>\(-72< -58=>3^2.\left(-2\right)^3< -58\)
\(\hept{\begin{cases}\left(-4\right)^3=-64\\\left|-6^2\right|=36\end{cases}=>-64< 36}=>\left(-4\right)^3< \left|-6^2\right|\)
\(3^2.\left(-2\right)^3=9.\left(-8\right)=\left(-72\right)\)
Vì (-72)<(-58) nên 32.(-2)3<(-58)
Có (-4)3 có gt âm
\(|-6^2|\)có gt dương
mà âm luôn luôn < dương
nên (-4)3<\(|-6^2|\)
a,\(4^n.2^n=512\)
\(\Rightarrow2^{2n}.2^n=512\Rightarrow2^{3n}=2^9\Rightarrow3n=9\Rightarrow n=3\)
b,\(3^n+3^{n+3}=252\)( sửa đề )
\(\Rightarrow3^n.\left(1+3^3\right)=252\Rightarrow3^n.28=252\Rightarrow3^n=9\Rightarrow n=2\)
c,\(2.3^{2x+2}=18\)
\(\Rightarrow3^{2n+2}=9\Rightarrow2n+2=2\Rightarrow n=0\)
d,\(x^2=2^3+3^2+4^3\)
\(\Rightarrow x^2=8+9+64\Rightarrow x^2=81\Rightarrow x^2=9^2=\left(-9\right)^2\Rightarrow x=9\)hoặc \(x=-9\)
e,\(x^5=x^9\)
\(\Rightarrow x^9-x^5=0\Rightarrow x^5.\left(x^4-1\right)=0\Rightarrow\hept{\begin{cases}x^5=0\\x^4-1=0\end{cases}\Rightarrow\hept{\begin{cases}x=0\\x=1\\x=-1\end{cases}}}\)
f,\(\left(x-4\right)^3=\left(x-4\right)^{10}\)
\(\Rightarrow\left(x-4\right)^{10}-\left(x-4\right)^3=0\Rightarrow\left(x-3\right)^3.\left[\left(x-3\right)^7-1\right]=0\)
\(\Rightarrow\hept{\begin{cases}\left(x-3\right)^3=0\\\left(x-3\right)^7=1\end{cases}\Rightarrow\hept{\begin{cases}x-3=0\\x-3=1\end{cases}\Rightarrow}\hept{\begin{cases}x=3\\x=4\end{cases}}}\)
\(c,-5\left(2-x\right)+4\left(x-3\right)=10x-15\)
\(-10+5x+4x-12=10x-15\)
\(5x+4x-10x-10-12=-15\)
\(-x-10=-3\)
\(-x=7\)
\(x=-7\)
Vậy \(x=-7.\)
Những câu khác bạn nên tự làm...
a) −7. (5 - x) − 2. (x − 10) = 15
-35 + 7x - 2x + 20 = 15
7x - 2x = 35 - 20 + 15
5x = 30
x = 30 : 5
x = 6
Vậy x = 6
b) 4. (2 − x) + 3(x − 5) = 14
8 - 4x + 3x - 15 = 14
8 - 15 - 14 = 4x - 3x
-21 = x
Vậy x = -21
c) −5. (2 − x) + 4. (x − 3) = 10x −15
-10 + 5x + 4x - 12 = 10x - 15
-10 - 12 + 15 = 10x - 5x - 4x
-7 = x
Vậy x = -7
d) −7. (3x − 5) + 2. (7x − 14) = 28
-21x + 35 + 14x - 28 = 28
35 - 28 - 28 = 21x - 14x
-21 = 7x
x = (-21) : 7
x = -3
Vậy x = -3
e) 5. (4 − x) − 7(−x + 2) = 4 − 9 + 3
20 - 5x + 7x - 14 = -2
-5x + 7x = -2 - 20 + 14
2x = -8
x = (-8) : 2
x = -4
Vậy x = -4
f) 5. (x − 7) + 10. (3 − x) = 20
5x - 35 + 30 - 10x = 20
-35 + 30 - 20 = -5x + 10x
-25 = 5x
x = (-25) : 5
x = -5
Vậy x = -5
g) −4. (x + 1) + 8. (x − 3) = 24
-4x - 4 + 8x - 24 = 24
-4x + 8x = 24 + 4 + 24
4x = 52
x = 52 : 4
x = 13
Vậy x = 13
h) 4. (x − 1) − 3. (x − 2) = −|−5|
4x - 4 - 3x + 6 = -5
4x - 3x = -5 + 4 - 6
x = -7
Vậy x = -7
x-0,27=(73/77+73/165+73/185):[25.12/133)
x-0,27=(73/77+73/165+73/185):[25/1.12/133)
x-0,27=(73/77+73/165+73/185):300/133
x-0,27=1387/777:300/133
x-0,27=0,791381381
x=0,791381381-0,27
x=0,521381381
a, \(x+17=14\)
\(x=-3\)
b, \(2x-6-3x+15=-18\)
\(-x+9=-18\)
\(-x=-27\)
\(x=27\)
x-(-17)=14
<=>x+17=14
<=>x=-3
Vậy x=-3
2(x-3)-3(x-5)=-18
<=>2x-6-3x+15=-18
<=>9-x=-18
<=>x=-27
Vậy x=-27