A) 297+150:(493-47×10+7)
B) 728:(73×3.54+0.17×25+3.54×27+0.23×25
tính nhanh
3.54*73+0.23*25+3.54*27+0.17*25
3.54*73+25*0.23-3.54*27+0.17+25
Làm hộ mình nhé
Tinh nhanh 354 x 73 + 0.23 x 25 +3.54 x 27 + 0.17 x 25
3.54 X 73 + 0.23 X 25 + 3.54 X 27 +0.77 X 25
3.54 X 73 + 0.23 X 25 + 3.54 X 27 +0.77 X 25
= 3.54X(73+27)+25X(0.23+0.77)
=354+25
=400
3,54.73+0,23.25+3,54.27+0,77.25
=(3,54.73+3,54.27)+(0,23.25+0,77.25)
=3,54.(73+27)+25.(0,23+0,77)
=3,54.100+25.1
=379
297+150÷(493-47×10+7)
290+150:(490-47x10+7)
=290+150:30
=290+5
=295
=297+150*(493-470+7)
=297+150*(23+7)
=297+150*30
=297+5
=302
297 + 150 : ( 493 - 47 x 10 + 7 )
= 297 + 150 : ( 493 - 470 + 7 )
= 297 + 150 : 30
= 297 + 5
= 302
Tìm x thuộc Z biết
a.27+(-17+×)=297-(12+297
b.25-(-2+×+25)=-(-10-397)+(-397-5)
c.(32-×)+(-7+/×/)-(/-×+25)=-45
a, 27+(-17+x)=297-(12+297)
27-17+x=297-12-297
10+x=-12
x=-22
b,25-(-2+x+25)= -(-10-397)+(-397-5)
25+2-x-25=10+397-397-5
2-x=5
x=-3
c, (32-x)+(-7+/x/)-(/-x/+25)=-45
* TH1: x>=0, ta có /x/=x , /-x/=-x
32-x+(-7+x)-(-x+25)=-45
32-x-7+x+x-25=-45
x=-45
*TH2:x<0, ta có /x/=-x, /-x/=x
32-x-7-x-x-25=-45
-3x=-45
x=15
Tính: 728: (73 x 3,54 + 0,17 x 25 +3,54 x 27 + 0,23 x25)
728 : ( 73 x 3,54 + 0,17 x 15 + 3,54 x 27 + 0,23 x 25 )
\(A=\dfrac{27^3.54^2}{108^4}\)
\(A=\dfrac{27^3.54^2}{108^4}\)
\(=\dfrac{\left(3^3\right)^3.\left(3^3.2\right)^2}{\left(2^2.3^3\right)^4}\)
\(=\dfrac{3^9.3^6.2^2}{2^8.3^{12}}\)
\(=\dfrac{3^{15}.2^2}{2^8.3^{12}}\)
\(=\dfrac{3^3}{2^5}=\dfrac{27}{32}\)
Vậy A =\(\dfrac{27}{32}\)