2 mũ 2 . 85 + 40 . 2 mũ 2 - 2 mũ 3
[(85-5):2 mũ 3 + 5 mũ 2]x2-40
[(85 - 5) : 2³ + 5²] . 2 - 40
= (80 : 8 + 25) . 2 - 40
= (10 + 25) . 2 - 40
= 35 . 2 - 40
= 70 - 40
= 30
[(85 - 5) : 2³ + 5²] . 2 - 40
= (80 : 8 + 25) . 2 - 40
= (10 + 25) . 2 - 40
= 35 . 2 - 40
= 70 - 40
= 30
[(85 - 5) : 2³ + 5²] . 2 - 40
= (80: 8 + 25) . 2 - 40
= (10 + 25) . 2 - 40
= 35 . 2 - 40
= 70 - 40
= 30
2 mũ 3 - 5 mũ 3 : 5 mũ 2 + 12 . 2 mũ 2
5 . [ { 85 - 35 : 7 } : 8 + 90 ] - 5 mũ 2 . 2
\(2^3-5^3:5^2+12\cdot2^2=8-5+48=51\\ 5\left[\left(85-35:7\right):8+90\right]-5\cdot2^2\\ =5\left(80:8+90\right)-20=5\cdot100-20=480\)
85+(-35)+(-12)+(-35)
5 mũ 3 . 4 mũ 2 + 85. 5 mũ 3 - 5 mũ 7 : 5 mũ 4
85+(-35)+(-12)+(-35)=50+(-12)+(-35)=38+(-35)=3
53.42+85.53-57:54=125.16+85.125-53=125.16+85.125-125
=125.16+85.125-125.1=(16+85-1).125=100.125=12500
Thực hiện phép tính a} 2 mũ 3 - 5 mũ 3 : 5 mũ 2 + 12.2 mũ 2 b} 5 . [ { 85 - 35 : 7 } : 8 + 90 ] - 5 mũ 2 . 2 c} 2 . [ { 7 - 3 mũ 3 : 3 mũ 2 } : 2 mũ 2 + 99 ] - 100 d} 2 mũ 7 : 2 mũ 2 + 5 mũ 4 : 5 mũ 3 . 2 mũ 4 - 3 . 2 mũ 5 e} { 3 mũ 5 . 3 mũ 7 } : 3 mũ 10 + 5 . 2 mũ 4 - 7 mũ 3 : 7
2 . [ { 7 -3 mũ 3 : 3 mũ 2 } : 2 mũ 2 + 99 ] - 100
b: \(5\cdot\left[\left(85-35:7\right):8+90\right]-5^2\cdot2\)
\(=5\cdot\left[\left(85-5\right):8+90\right]-25\cdot2\)
\(=5\cdot\left(10+90\right)-50\)
=450
5 mũ 12. 7- 5 mũ 11 . 10
2 mũ 20. 15+2 mũ 20 . 85
125 mũ 3 : 25 mũ 4
24 mũ 4 : 3 mũ 4 - 32 mũ 12 : 16 mũ 12
\(5^{12}.7-5^{11}.10\)
\(=5^{11}.\left(5.7-10\right)\)
\(=5^{11}.25\)
\(=5^{11}.5^2\)
\(=5^{13}\)
\(2^{20}.15+2^{20}.85\)
\(=2^{20}.5\left(3+17\right)\)
\(=2^{20}.100\)
\(=104857600\)
\(125^3:25^4\)
\(=\left(5^3\right)^3:\left(5^2\right)^4\)
\(=5^9:5^8\)
\(=5\)
\(24^4:3^4-32^{12}:16^{12}\)
\(=\left(24:3\right)^4-\left(32:16\right)^{12}\)
\(=8^4-2^{12}\)
\(=0\)
4 mũ n+2 + 4 mũ n+3 + 4 mũ n+4 + 4 mũ n+5 = 85 x (2 mũ 2019 : 2 mũ 2015)
\(4^{n+2}+4^{n+3}+4^{n+4}+4^{n+5}=85.\left(2^{2019}\div2^{2015}\right)\)
\(\Leftrightarrow4^{n+2}\left(1+4^1+4^2+4^3\right)=85.2^{2019-2015}\)
\(\Leftrightarrow4^{n+2}.85=85.2^4\)
\(\Leftrightarrow4^{n+2}=2^4=4^2\)
\(\Leftrightarrow n+2=2\)
\(\Leftrightarrow n=0\)
Bài 1:
29.(85-47)+85.(47-29)
=29.38+85.18
=1102+1530
=2632
BÀI 2
a, 15x = -75
x =( -75) : 15
x = -5
Vậy x= -5
b,-5x+8=-27
-5x = -27 - 8
-5x= -35
x =-35 : -5
x = 7
Vậy x = 7
c,3.(17 + x ) = - 42
17 + x = - 42 : 3
17 + x = -14
x = - 14 - 17
x = -31
Vậy x = - 31
d,-10 -( 2x -16) = 0
2x - 16 = 10-0
2x - 16 = 10
2x = 10 +16
2x = 26
x = 26 : 2
x = 13
Vậy x = 13
e,( mik ko bít làm)
f,( tự làm nghen bạn)
c)2 mũ 10 x 15 +2 mũ 10 x 85
d)5 mũ 12x 7-5 mũ 11x 10
e)24 mũ 4: 3 mũ 4 -32 mũ 12 :16 mũ 12
f)(5 mũ 3 + 5 mũ 4 +125 mũ 2 ):5 mũ 3
2(mũ 2) x 85 + 15 .2(mũ 2) - 2020 (mũ 0)
Lời giải:
$2^2.85+15.2^2-2020^0=4.85+15.4-1$
$=4(85+15)-1=4.100-1=400-1=399$
22.85+15.22−20200=4.85+15.4−122.85+15.22−20200=4.85+15.4−1
=4(85+15)−1=4.100−1=400−1=399