Răspuns :
5xla2plus 5x plus 7x plus 7
se dă factor comun
5 (5x plus1)plus7 (x plus 1)
se dă factor comun
(5x plus 1)(5plus7
se dă factor comun
5 (5x plus1)plus7 (x plus 1)
se dă factor comun
(5x plus 1)(5plus7