Question

(3x+5) ``Totu` la patrat.`` - (x+1) `` Totu` la patrat.`` . Repede va rog, mersi :*

Answer 1

$(3x+5)^2-(x+1)^2= \\ =(3x)^2+2 \cdot 3x \cdot 5+5^2-(x^2+2 \cdot x \cdot 1 +1^2)= \\ =9x^2+30x+25-(x^2+2x+1)=9x^2+30x+25-x^2-2x-1= \\ =8x^2+28x+24$