Question

Equações
(0,5)a) 3x + 4-5x=-8x -20



(0,5)b) 9x elevado a 2 = 4


(1,0)c) x elevado a 2 + 19x -20= 0

Answer 1

a) 3x+8x-5x= -20-4
4x= -24
x= -24/4
x= -6

b) 9x²=4
9x= √4
9x=2
x= 2/9

x²+19x-20=0
a= 1 b= 19 c= -20

19²-4.1.(-20)
361+80=
441

(-19+√441)/2.1
(-19+21)/2
2/2 = 1

(-19-√441)/2.1
(-19-21)2
-40/2
-20

S= {-20,1}