a,x mũ 2 y mũ4 -2xymũ2+1
b,a.b+1/4+a mũ 2 bmũ2
c,4+4x+xmũ2
d,x mũ 2 y mũ2+2xy+1
bài 2: a,x mũ 2 +2x+1+(x-1) mũ 2
b,(x+y) mũ 2/x+y
c,(x+y) mũ 2+(x-y) mũ 2 +2(x-y)(x+y)/2x mũ 2
d,(x.y) mũ 3 -(x+y) mũ 3
a,x mũ 2 y mũ4 -2xymũ2+1
b,a.b+1/4+a mũ 2 bmũ2
c,4+4x+xmũ2
d,x mũ 2 y mũ2+2xy+1
bài 2: a,x mũ 2 +2x+1+(x-1) mũ 2
b,(x+y) mũ 2/x+y
c,(x+y) mũ 2+(x-y) mũ 2 +2(x-y)(x+y)/2x mũ 2
d,(x.y) mũ 3 -(x+y) mũ 3
Đáp án:
$\begin{array}{l}
a){x^2}{y^4} – 2x{y^2} + 1 = {\left( {x{y^2} – 1} \right)^2}\\
b)\frac{{ab + 1}}{{4 + {a^2}{b^2}}}\\
c)4 + 4x + {x^2}\\
= {\left( {x + 2} \right)^2}\\
d){x^2}{y^2} + 2xy + 1\\
= {\left( {xy + 1} \right)^2}\\
B2)a){x^2} + 2x + 1 + {\left( {x – 1} \right)^2}\\
= {x^2} + 2x + 1 + {x^2} – 2x + 1\\
= 2{x^2} + 2\\
= 2\left( {{x^2} + 1} \right)\\
b)\frac{{{{\left( {x + y} \right)}^2}}}{{x + y}} = x + y\\
c)\frac{{{{\left( {x + y} \right)}^2} + {{\left( {x – y} \right)}^2} + 2\left( {x – y} \right)\left( {x + y} \right)}}{{2{x^2}}}\\
= \frac{{{{\left( {x + y + x – y} \right)}^2}}}{{2{x^2}}}\\
= \frac{{{{\left( {2x} \right)}^2}}}{{2{x^2}}}\\
= \frac{{4{x^2}}}{{2{x^2}}}\\
= 2\\
d){\left( {x.y} \right)^3} – {\left( {x + y} \right)^3}\\
= \left( {x.y – x – y} \right)\left( {{x^2}{y^2} + xy\left( {x + y} \right) + {{\left( {x + y} \right)}^2}} \right)\\
= \left( {xy – x – y} \right)\left( {{x^2}{y^2} + {x^2}y + x{y^2} + {x^2} + 2xy + {y^2}} \right)
\end{array}$