Câu 4:
a: Đúng(Quy tắc ba điểm)
b: \(\overrightarrow{AB}+\overrightarrow{CD}-\overrightarrow{AD}-\overrightarrow{CB}\)
\(=\overrightarrow{AB}+\overrightarrow{BA}-\overrightarrow{AD}-\overrightarrow{DA}=\overrightarrow{0}-\overrightarrow{0}=\overrightarrow{0}\)
=>Đúng
Câu 1:
B={x\(\in\)R||x|>=10}
=>B=(-\(\infty\);10]\(\cup\)[10;+\(\infty\))
mà A=[-10;1)
nên A\(\cup\)B=(-\(\infty\);1)\(\cup\)[10;+\(\infty\))
=>\(C_R\left(A\cup B\right)=R\backslash\left[\left(-\infty;1\right)\cup[10;+\infty)\right]\)
=>\(C_R\left(A\cup B\right)=[1;10)\)
=>a=1; b=10
T=a+b=1+10=11