Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a)100-7.[x-5]=58
7.[x-5]=100-58=42
x-5=42:7=6
x=6+5
x=11
b)12.[x-1]:3=43+23
12 [x-1]:3=64+8
12.[x-1]:3=72
[x-1]:3=72:12=6
[x-1]=6.3=18
x=18-1
x=17
tao koooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo biếtttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttt
Bài 1: a) \(M=1+5+5^2+...+5^{100}\)
\(5M=5+5^2+5^3+...+5^{101}\)
\(5M-M=\left(5+5^2+5^3+...+5^{101}\right)-\left(1+5+5^2+...+5^{100}\right)\)
\(4M=5^{101}-1\)
\(M=\frac{5^{101}-1}{4}\)
b) \(N=2+2^2+...+2^{100}\)
\(2N=2^2+2^3+...+2^{101}\)
\(2N-N=\left(2^2+2^3+...+2^{101}\right)-\left(2+2^2+...+2^{100}\right)\)
\(N=2^{101}-2\)
Bài 2:
a) \(16^{32}=\left(2^4\right)^{32}=2^{128}\)
\(32^{16}=\left(2^5\right)^{16}=2^{80}\)
Vì \(2^{128}>2^{80}\Rightarrow16^{32}>32^{16}\)
a) \(5.3^x=405\)
\(\Rightarrow3^x=405:5\)
\(\Rightarrow3^x=81=3^4\)
\(\Rightarrow x=4\)
b) \(\left(x-2\right)^5=243\)
\(\Rightarrow\left(x-2\right)^5=3^5\)
\(\Rightarrow x-2=3\)
\(\Rightarrow x=5\)
c) \(2^x+2^{x+4}=272\)
\(\Rightarrow2^x.\left(1+2^4\right)=272\)
\(\Rightarrow2^x.17=272\)
\(\Rightarrow2^x=272:17=16\)
\(\Rightarrow2^x=2^4\)
\(\Rightarrow x=4\)
d) Từ x + 1 đến x + 2 có số số hạng là: (30 - 1) : 1 + 1 = 30 (số)
\(\left(x+1\right)+\left(x+2\right)+...+\left(x+30\right)=795\)
\(\Rightarrow30x+\frac{\left(30+1\right).30}{2}=795\)
\(\Rightarrow30x+465=795\)
\(\Rightarrow30x=330\)
\(\Rightarrow x=330:30\)
\(\Rightarrow x=11\)
a) \(5.3^x=405\)
\(3^x=\frac{405}{5}=81\)
\(3^x=3^4\)
Vậy x = 4
b ) \(\left(x-2\right)^5=243\)
\(\left(x-2\right)^5=3^5\)
\(\Rightarrow x-2=3\)
\(\Rightarrow x=3+2=5\)
Vậy x = 5
a)64:2mũ5×30×4
= 64 : 32 x 30 x 4
= 240
b)3 mũ 2× 5 - 2 mũ 2×7+2 mũ 0 × 5
= 9 x 5 - 4 x 7 + 1 x 5
= 45 - 28 + 5
= 22
c)2 mũ 3-5 mũ 3÷5 mũ 2 + 12×2 mũ 2
= 8 - 125 : 25 + 12 x 4
= 8 - 5 + 48
= 51
d)2[(7-3 mũ 3÷3 mũ 2) chia 2 mũ 2 + 99]-100
= 2[( 7 - 27 : 9) : 4 + 99] - 100
= 2[4 : 4 + 99] - 100
= 2. 100 - 100
= 200 - 100
= 100
e)4[(3 + 3^7:3^4)chia 10 + 97]-300
= 4[( 3 + 3^3) : 10 + 97] - 300
= 4[ 30 : 10 + 97 ] - 300
= 4. 100 - 300
= 400 - 300
= 100
f)2^2 x 5 [(5 mũ 2 cộng 2 mũ 3) chia 11 - 2] - 3^2 x 2
= 4 x 5 [ (25 + 8 ) : 11 - 2] - 9 x 2
= 20 [ 33 : 11 - 2] - 18
= 20. 1 - 18
= 20 - 18
= 2
ai k mình k lại [ chỉ 3 người đầu tiên mà trên 10 điểm hỏi đáp ]
A.x=11
B.=47
bạn làm chi tiết đi