Question

produtos notáveis (3x+2) ?

Answer 1

$(3x+2 )^{2} \to (3x+2).(3x+2)\to 9 x^{2} +6x+6x+4\to\\ \\9 x^{2} +12x+4=0\\\\a=9;b=12;c=4\\\\ \Delta= b^{2} -4.a.c\to \Delta= 12^{2} -4.9.4\to \Delta=144-144\to \Delta=0\\\\x= \frac{-b+- \sqrt{\Delta} }{2.a} \to x= \frac{-12+- \sqrt{0} }{2.9}\to x= \frac{-12+-0}{18}\\ \\x'=x''= \frac{-12}{18}\to x'=x''= -\frac{2}{3}\\\\\\S=( -\frac{2}{3})$