Question

2x(x+3)=x²+3x+70 me ajudem por favoooooorrrrrrr

Answer 1

2x (x +3) = x² +3x +70
2x² +6x = x² +3x +70
2x² -x² +6x -3x = 70
x² +3x = 70
x² +3x -70
Δ= b² -4ac
Δ= 3² -4.1.(-70)
Δ= 9 +280
Δ= 289

x= -b +/- √Δ / 2a
x= -3 +/- √289 / 2.1
x'= -3 + 17 / 2
x'= 14/2
x'= 7

x''= -3 -17 /2
x''= -20/2
x''= -10

Bons estudos!

Answer 2

2x²+6x=x²+3x+70
2x²-x²+6x-3x-70=0
x²+3x-70=0
Δ=b²-4ac
Δ=3²-4.1.(-70)
Δ= 9+280
Δ= 289
x=-b+-√Δ
     2.a
x=-3+-√289
       2.1
x=-3+-17
        2
x'=-3+17 = 14 = 7
        2        2
x"=-3-17 = -20 = -10
        2        2
S=(-10, 7)