Question

 (1-X)^{2 = ?} 

(3a-1)²=?

(5-3b)=? 

(y-3).(y+3) =? giúp mk vs mọi người :)

Answer 1

\(\left(1-x\right)^2=1-2x+x^2\)

\(\left(3a-1\right)^2=9a^2-6a+1\)

\(\left(5-3b\right)^2=25-30b+9b^2\)

\(\left(y-3\right)\left(y+3\right)=y^2-9\)

Answer 2

\(\left(1-x\right)^2=1-2x+x^2\)
\(\left(3a-1\right)^2=\left(3a\right)^2-2.3a.1+1^2=9a^2-6a+1\)

\(\left(5-3b\right)^2=5^2-2.5.3b+\left(3b\right)^2=25-30b+9b^2\)
\(\left(y-3\right).\left(y+3\right)=y^2-3^2=y^2-9\)