Test 1- Formule de calcul prescurtat

= $a^2-2ab+b^2$  

= $a^2+b^2$  

= $a^2+2ab+b^2$  

= $a^2+2ab-b^2$  

= $x^2+y^2$  

= $x^2-2xy+y^2$  

= $x^2-y^2$  

= $y^2-x^2$  

= $a^2+2ab+b^2$  

= $a^2-2ab+b^2$  

= $a^2-2ab-b^2$  

= $a^2-b^2$  

= $9+6x+x^2$  

= $9-x^2$  

= $9-6x+x^2$  

= $9-6x-x^2$  

= $a^2+25$  

= $a^2+10a+25$  

= $a^2+10a-25$  

= $a^2-10a-25$  

= $2-x^2$  

= $2-2x$  

=  $4-x^2$  

= $2-2\sqrt{2}x+x^2$  

 $\left(2x+\sqrt{5}\right)\left(2x-5\right)=4x^2-5$  

 $\left(2x+\sqrt{5}\right)\left(2x-\sqrt{5}\right)=4x^2-5$  

 $\left(2x+\sqrt{5}\right)\left(2x-\sqrt{5}\right)=2x^2-5$  

 $\left(2x+\sqrt{5}\right)\left(2x-\sqrt{5}\right)=4x^2-\sqrt{5}$  

 $9+\sqrt{2}$  

 $11+\sqrt{2}$  

 $11+6\sqrt{2}$  

 $5+6\sqrt{2}$  

 $6x-16$  

 $9x^2-16$  

 $9x^2-12x+16$  

 $9x^2-24x+16$