Question

Alguém poderia me ajudar? Preciso muito

Answer 1

a)x²+3=4x

x²-4x+3=0

∆=b²-4.a.c

∆=(-4²)-4.1.3

∆=16-12

∆=4

x= -b±√∆/2.a

x= -(-4)±√4/2.1

x= 4±2/2

x'= 4+2/2 x"= 4-2/2

x'= 6/2 x"= 2/2

x'= 3 x''= 1

s={1,3}

b)x²+x-20=0

∆=b²-4.a.c

∆=1²-4.1.(-20)

∆=1+80

∆=81

x= -b±√∆/2.a

x= -1±√9/2.1

x= -1±9/2

x'= -1+9/2 x"= -1-9/2

x'= 8/2 x"= -10/2

x'= 4 x''= -5

S={4,-5}

c)2x²-98=0

2x²=98

2x=98/2

x²=49

x=±√49

x=±7

s={+7,-7}