1--7 a^2+2a+5
2-9y la a doua+6y-6y-4=9y la a doua-4
b_16x^2-9y^2
3-b^2-16b+64-64+6b=bla a doua-10b.
b: x^2-y^2-x^2-3y^2=-4y^2
c: desfiintezi parantezele, iar in urma calculeleor obtii a^2+8
d
: y la a doua+ 4y+4 -2y la a doua -4y=-y^2+4
4: 3x(x+3y)
(5-y)(5+y)
d: (a-3b) la a doua
e: 8x la a doua+2x-1
5: nu inteleg text, frac, arcolade?
6b=b^2-16b