Question

socorroooo, me ajudemmm​

Answer 1

1)

x*(x+6)=27

x²+6x-27=0

x'=[-6+√(36+108)]/2=(-6+12)/2=3

x''=[-6-√(36+108)]/2=(-6-12)/2=-9<0 , não serve

x=3  m

x+6=9  m

2)

(x+16)*x=80

x²+16x-80=0

x'=[-16+√(256+320)]/2=(-16+24)/2 = 4

x''=[-16+√(256+320)]/2=(-16-24)/2 = -20< 0

x=4 m

x+16 =20 m

3)

a)

x²+6x-16=0

x²+6x+3²-3²-16=0

(x+3)²-9-16=0

(x+3)²=25

x+3=±√25

x=-3±5

x'=-8

x''=2

b)

x²+8x+16=0

(x+4)²=0

x+4=0

x'=x''=-4

c)

x²+8x-48=0

x²+8x+4²-4²-48=0

(x+4)²-16-48=0

(x+4)²=64 ==>x+4=±√64=±8

x=-4±8

x'=-12

x''=4

4)

x²+6*x=16

x²+6x-16=0

x'=[-6 + √(36+64)]/2 =(-6+10)/2 =2

x''=[-6 - √(36+64)]/2 =(-6-10)/2 =-8<0

letra D