Question

2x =15 -x elevado a 2

Answer 1

2x=15-x²
x²+2x-15=0
Δ=2²-4×1×(-15)
Δ=4+60
Δ=64

X=$\frac{-2+₋ \sqrt{64} }{2×1}$
X=$\frac{-2+₋8}{2}$

X'=$\frac{-2+8}{2}$
X'=$\frac{6}{2}$
X'=3

X"=$\frac{-2-8}{2}$
X"=$\frac{-10}{2}$
X"=-5

Answer 2

olá!

2x = 15 - x²

2x + x²  = 15

x² + 2x = 15

agora usaremos a formula de bhaskara:

x = - 2 +-√ 2² - 4.1.(-15)

    ---------------------------------

                  2.1

x =  -2 +-√ 4 +60

  -----------------------------------

                2

x = - 2+- √ 64

   -------------------------

            2

x = - 2+- 8

     -------------

          2

x = - 2 +8                                6  

   -------------- =    >>     x =  --------   >>    x =  3

         2                                   2

  

          -2 - 8                       -10  

x =  -------------  =   >>    ----------   >>    x = -5

            2                            2

s = { 3 , -5 }

Bons estudos!