BT1: Khai triển

\(a,\left(\dfrac{x^2}{2}+y^2\right)^2\)

\(b,\left(\dfrac{4}{5}x^2-\dfrac{2}{3}y\right)^2\)

\(c,\left(2x+\dfrac{1}{2}\right)\left(2x-\dfrac{1}{2}\right)\)

BT8: Tìm x, biết

\(a,\left(x-2\right)\left(x-3\right)=0\)

\(b,x^2-5x=0\)

\(c,x^2-9=0\)

\(d,4x^2-25=0\)

BT7: Tìm x, biết

\(a,x^2+2x+1=9\)

\(b,x^2-4x-21=0\)

\(c,x^2+10x-24=0\)

BT9: Tìm x biết

\(9,\left(2x-5\right)^2-\left(x+1\right)^2=0\)

\(10,\left(x+3\right)^2-x^2=45\)

\(11,\left(5x-4\right)^2-49x^2=0\)

\(12,16\left(x-1\right)^2-25=0\)

BT9: Tìm x biết

\(5,4x^2-36=0\)

\(6,4x^2-36=0\)

\(7,\left(3x+1\right)^2-16=0\)

\(8,\left(2x-3\right)^2-49=0\)

BT9: Tìm x biết

\(1,x^2-9=0\)

\(2,25-x^2=0\)

\(3,-x^2+36=0\)

\(4,4x^2-4=0\)