Question

qual o resultado de: 5x^2_4x=12
​

Answer 1

5x² - 4x =12

5x² - 4x - 12 = 0

Coeficientes:

A= 5

B= - 4

C= - 12

∆= b² - 4ac

∆= ( - 4)² - 4 • 5 • ( - 12)

∆= 16 + 240

∆= 256

x= - b ± √∆ / 2a

x= - ( - 4) ± √256 / 2 • 5

x= 4 ± 16 / 10

x'= 4 + 16 / 10 = 20/10 = 2

x"= 4 - 16 / 10 = - 12/10(÷2) = - 6/5

S= ( - 6/5 , 2)

Answer 2

Olá!

$5 {x}^{2} - 4x = 12 \\ 5 {x}^{2} - 4x - 12 = 0$

$a = 5 \\ b = ( - 4) \\ c = ( - 12)$

$\Delta = {b}^{2} - 4ac \\ \Delta = {( - 4)}^{2} - 4 \times 5 \times ( - 12) \\ \Delta = 16 + 240 \\\Delta = 256$

$x = \frac{ - b\pm \sqrt{\Delta} }{2a} \\ \\ x = \frac{ - ( - 4)\pm \sqrt{256} }{2 \times 5} \\ \\ x = \frac{4\pm16}{10}$

$x_{1} = \frac{4 + 16}{10} = \frac{20}{10} = 2 \\ \\ x_{2} = \frac{4 - 16}{10} = - \frac{ {12}^{ \div 2} }{ {10}^{ \div 2} } = - \frac{6}{5}$

$S = \{ - \frac{6}{5} , 2 \}$

Espero ter ajudado! :)