Question

( CESGRANRIO)o número de raizes reais de 3x (2x 2 -7x+5=1​

Answer 1

${3}^{2 {x}^{2} - 7x + 5 } = 1 \\ {3}^{2 {x}^{2} - 7x + 5 } = {3}^{0} \\ 2 {x}^{2} - 7x + 5 = 0$

$\Delta = {b}^{2} - 4ac \\ \Delta = {( - 7)}^{2} - 4.2.5 \\ \Delta = 49 - 40 \\ \Delta = 9$

$x= \frac{-b±\sqrt{\Delta} }{2a} \\ x = \frac{ - ( - 7)± \sqrt{9} }{2.2} \\ x = \frac{7±3}{4}$

$x' = \frac{7 + 3}{4} = \frac{10 \div 2}{4 \div 2} = \frac{5}{2} \\ x'' = \frac{7 - 3}{4} = \frac{4}{4} = 1$

S={5/2,1}