Răspuns:
Explicație pas cu pas:
[tex]\bf \big(3x +5\big)^2= \big(3x +5\big)\cdot\big(3x +5\big)=[/tex]
[tex]\bf \big(3x\big)^2+2\cdot3x\cdot 5 +5^2=[/tex]
[tex]\red{\underline{~\bf 9x^2+ 30x +25~}}[/tex]
