Bài 1:
a: A={30;31;...;39}
b: B={0;1;2;...;11}
Bài 1:
\(a,A=\left\{30;31;...;39\right\}\\ b,B=\left\{0;1;2;...;10;11\right\}\)
Bài 3:
\(a,\Rightarrow x-15=75\Rightarrow x=90\\ b,\Rightarrow3x-8=2^4:2^3:2=1\Rightarrow3x=9\Rightarrow x=3\\ c,\Rightarrow3x-16=2\cdot7^4:7^3=14\Rightarrow3x=30\Rightarrow x=10\\ d,\Rightarrow215-x=100\Rightarrow x=115\\ e,\Rightarrow41-2x+5=18\Rightarrow2x=28\Rightarrow x=14\\ g,\Rightarrow100x+\left(1+2+...+100\right)=5750\\ \Rightarrow100x+5050=5750\\ \Rightarrow100x=700\Rightarrow x=7\)
Bài 5:
\(a,=36-16+4=24\\ b,=90:\left[5\left(10-2^2\right)\right]=90:\left(5\cdot6\right)=90:30=3\\ c,=987\left(32+68\right)=98700\\ d,=\dfrac{\left(2^3\cdot3^2\right)^3\cdot\left(2\cdot3^3\right)^2}{\left(2^2\cdot3^3\right)^4}=\dfrac{2^9\cdot3^6\cdot2^2\cdot3^6}{2^8\cdot3^{12}}=2^3=8\\ e,=\left(36^2-296\right):2=1000:2=500\\ g,=\dfrac{\dfrac{\left(101+1\right)\left(101-1+1\right)}{2}}{\left(101-100\right)+...+\left(3-2\right)+1}=\dfrac{5151}{1+...+1+1}=\dfrac{5151}{1\cdot51}=\dfrac{51\cdot101}{51}=101\)
