Question

Vă rog (✓3-✓12)^2-(✓7+✓11)( ✓11-✓7)=
Cere de

Answer 1

=3-2√36+12-11+7=3-12+8=-1

Answer 2

Hei. (✓3-✓12)^2 ii fix acelasi chestie ca si  formula (a-b)^2
(a-b)^2= a^2-2ab+b^2 adica.
(✓3-✓12)^2= (✓3)^2-2(✓3)(✓12)+(✓12)^2=
= 3-2✓36+12=
=3-12+12=
=3
partea a doua:
(✓7+✓11)( ✓11-✓7) nu ii acelasi ca si formula (a+b)(a-b) deci o sa facem cu metoda fundamentala.
(✓7+✓11)( ✓11-✓7)= (✓7)(✓11)-✓49 +(✓11)(✓11)-(✓11)(✓7)=
=✓77-7+✓121-✓77= ✓77-7+11-✓77=
=-7+11=4

Deci in sfarsit : 3-4= -1