Question

Exercitiul 8 dau coroana va rog​

Answer 1

a)(x²)²-10x²+9=0

x²=t

t²-10t+9=0

a=1

b=-10

c=9

∆=b²-4*a*c

∆=(-10²)-4*1*9=100-34=64

∆=-b+✓∆/2a=-(-10)+8/2=18/2=9

t2=-b-✓∆/2a=-(-10)-8/2=1

la b si c tot așa faci cu ∆

b)

(x²)²+2x²-3=0

x²=t

t²+2x-3=0

a=1,b=2,c=-3

∆=b²-4*a*c=>2²-4*1*(-3)=4+12=16

x1=-2+4/2=1

x2=-2-4/2=-3

c)

(x2)²+2x²-8=0

t²+2t-8=0

a=1,b=2,c=-8

b²-4*a*c=>2²-4*1*(-8)=4+32=36

x1=-2+6/2=2

x2=-2-6/2=-4