Question

me ajudem nessas 3 questões(2,3,3) por favorrrr!​

Answer 1

2) x+x^2=90

Fórmula de Baskhara

x^2+x-90=0

a= 1

b= 1

c= -90

∆=b^2-4.a.c

∆=1-4.1.(-90)

∆=1+360

∆=361

x'=-b+-√∆/2a

x'=-1+19/2

x'=18/2

x'=9

x"=-1-19/2

x"=-20/2

x"=-10

S={-10, 9}

3) x^2+x=12

x^2+x-12=0

a=1

b=1

c=-12

∆=b^2-4.a.c

∆=1-4.1.(-12)

∆=1+48

∆=49

x'=-b+-√∆/2a

x'=-1+7/2

x'=6/2

x'=3

x"=-1-7/2

x"=-8/2

x"=-4

S={-4, 3}

3) x^2-2x=-1

x^2-2x+1=0

a=1

b=-2

c=1

∆=b^2-4ac

∆=4-4.1.1

∆=4-4

∆=0

x=-b+-√∆/2

x=-(-2)+0/2

x=2/2

x=1