bài 3: Thực hiện phép tính
1) 15.93 : 27 - 62.12 +18.41
2) 18.73 +9.26 :8 - 12.7
3) 23.25 +288.42 :12
4) 122 : 36+ 82 : 4 -5.3
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(x+10\%\cdot x+20\%\cdot x+30\%\cdot x=4,8\)
=>\(x\left(1+0,1+0,2+0,3\right)=4,8\)
=>\(x\cdot1,6=4,8\)
=>\(x=4.8:1.6=3\)
\(B=\left[\left(-0,5\right):0,07-0,2:0,07\right]\cdot1,5-2024^0\\ =\left[\left(-0,5\right):\dfrac{7}{100}-0,2:\dfrac{7}{100}\right]\cdot1,5-1\\ =\left[\left(-0,5\right)\cdot\dfrac{100}{7}-0,2\cdot\dfrac{100}{7}\right]\cdot1,5-1\\ =\dfrac{100}{7}\cdot\left(-0,5-0,2\right)\cdot1,5-1\\ =\dfrac{100}{7}\cdot-0,7\cdot1,5-1\\ =\dfrac{100}{7}\cdot\dfrac{-7}{10}\cdot1,5-1\\ =-10\cdot1,5-1\\ =-15-1\\ =-16\)
\(1+3+5+...+x=36\\\left[ \left(x-1\right):2+1\right]\cdot\left(x+1\right):2=36\\ \dfrac{x-1+2}{2}\cdot\dfrac{x+1}{2}=36\\ \dfrac{x+1}{2}\cdot\dfrac{x+1}{2}=36\\ \dfrac{\left(x+1\right)^2}{4}=36\\ \left(x+1\right)^2=36\cdot4=144\)
TH1: x + 1 = 12 => x = 11
TH2: x + 1 = -12 => x = -13
Vì: x phải lớn hơn 0 => x = 11
\(A=2^2+2^4+2^6+...+2^{200}\\ 2^2A=2^4+2^6+...+2^{202}\\ 4A-A=\left(2^4+2^6+2^8+...+2^{202}\right)-\left(2^2+2^4+2^6+...+2^{200}\right)\\ 3A=2^{202}-2^2\)
\(=>3A+4=2^{202}-2^2+4=2^{202}-4+4=2^{202}\)
\(=>2^{202}=4^n\\ =>2^{202}=\left(2^2\right)^n\\ =>2^{202}=2^{2n}\\ =>2n=202\\ =>n=101\)
1) 15.9^3 : 27 - 6^2.12 +18.41
= 15.729 : 27 - 36.12 +738
= 10935 : 27 - 432 + 738
= 405 - 432 + 738
= 711
2) 18.7^3 + 9.2^6 :8 - 12.7
= 18.343 + 9.64 :8 - 84
= 6174 + 72 - 84
= 6162
3) 23.2^5 + 288.4^2 :12
= 23.32 + 288.16 :12
= 736 + 384
= 1120
4) 12^2 : 36 + 8^2 : 4 - 5.3
= 144 : 36 + 64 : 4 - 15
= 4 + 16 - 15
= 5