Question

3xelevado a 2+5=x (x-3)+10

Answer 1

$3 x^{2} +5=x(x-3)+10\\\\\\ 3 x^{2} +5= x^{2} -3x+10\to \\\\ 3 x^{2} +5- x^{2} +3x-10=0\to \\\\ 2 x^{2} +3x-5=0\\\\ a=2;b=3;c=-5\\\\\\ \Delta=b^2-4ac\to \Delta=3^2-4*2*(-5)\to \Delta=9+40\to \Delta=49\\\\\\ x' \neq x''\\\\\\ x= \frac{-b \pm \sqrt{ \Delta} }{2a} \to x= \frac{-3 \pm \sqrt{49} }{2*2} \to x= \frac{-3 \pm 7 }{4} \to \\\\\\ x'= \frac{-3+ 7 }{4} \to x'= \frac{4 }{4} \to x'=1\\\\\\ x''= \frac{-3 -7 }{4} \to x''= \frac{-10}{4} \tox''= \frac{-5}{2} \\\\\\ S=( \frac{-5}{2} ;1)$


Espero ter ajudado...

Answer 2

3x² + 5 = x(x - 3) + 10
3x² + 5 = x² - 3x + 10
3x² - x² + 3x + 5 - 10 = 0
2x² + 3x - 5 = 0
a = 2; b = 3; c = - 5

Δ = b² - 4ac
Δ = 3² - 4.2.(-5)
Δ = 9 - 8.(-5)
Δ = 9 + 40
Δ = 49

x =  - b +/- √Δ = - 3 +/- √49
            2a              2.2

x = - 3 + 7 = 4/4 = 1
          4

x =  - 3 - 7 = - 10 (:2)  =  - 5
          4          4  (:2)        2

R.: x = 1 e x = - 5
                       2