a) 2(2x+3)2=12x ∣⋅2
(2x+3)2=24x
4x2+12x+9=24x ∣−24x
4x2−12x+9=0
Δ=(−12)2−4⋅4⋅9=144−144=0
x=2⋅4−(−12)=812=23=121
b) (x−23)2−41=4−32x
x2−3x+49−41=4−32x
x2−3x+48=4−32x
x2−3x+2−4+32x=0
x2−231x−2=0
x2−37x−2=0
Δ=(−37)2−4⋅1⋅(−2)=949+8=949+972=9121
Δ=311
x1=2⋅1−(−37)−311=237−311=2−34=(−34):12=(−34)⋅21=−64=−32
x2=2⋅1−(−37)+311=237+311=2318=26=3 x2=2⋅1−(−37)+311=237+311=2318=26=3
c) 21(1−6x)2=2(x−0,5)(x+0,5)
21(1−12x+36x2)=2(x2−41)
21−6x+18x2=2x2−21
21−6x+18x2−2x2+21=0
16x2−6x+1=0
Δ=(−6)2−4⋅16⋅1=36−64=−28
Brak rozwiązań.
d) 31(4x−3)(4x+3)=6x
31(16x2−9)=6x ∣⋅3
16x2−9=18x
16x2−18x−9=0
Δ=(−18)2−4⋅16⋅(−9)=324+576=900
Δ=30
x1=2⋅16−(−18)−30=3218−30=32−12=−83
x2=2⋅16−(−18)+30=3218+30=3248=23=121
e) 4x2−36x+8=31(x+1)(2x−3) ∣⋅3
12x2−(6x+8)=(x+1)(2x−3)
12x2−6x−8=2x2−3x+2x−3
12x2−6x−8−2x2+3x−2x+3=0
10x2−5x−5=0 ∣:5
2x2−1x−1=0
Δ=(−1)2−4⋅2⋅(−1)=1+8=9
Δ=3
x1=2⋅2−(−1)−3=41−3=4−2=−21
x2=2⋅2−(−1)+3=41+3=44=1
f) 5(x−2)2+10x(x+3)=0,3x(2x−1) ∣⋅10
2(x−2)2+x(x+3)=3x(2x−1)
2(x2−4x+4)+x2+3x=6x2−3x
2x2−8x+8+x2+3x−6x2+3x=0
−3x2−2x+8=0
Δ=(−2)2−4⋅(−3)⋅8=4+96=100
Δ=10
x1=2⋅(−3)−(−2)−10=−62−10=−6−8=34=131
x2=2⋅(−3)−(−2)+10=−62+10=−612=−2
g) 2(1−3x)2−3x(4−x)=65+2x+9 ∣⋅6
3(1−3x)2−2x(4−x)=5+3(x+9)
3(1−6x+9x2)−8x+2x2=5+3x+27
3−18x+27x2−8x+2x2=32+3x
29x2−26x+3−32−3x=0
29x2−29x−29=0 ∣:29
x2−x−1=0
Δ=(−1)2−4⋅1⋅(−1)=1+4=5
Δ=5
x1=2⋅1−(−1)−5=21−5
x2=2⋅1−(−1)+5=21+5
h) 31x2+5(x+2)2=5(x−1)(x+1)+x−2 ∣⋅15
5x2+3(x+2)2=3(x−1)(x+1)+15x−30
5x2+3(x2+4x+4)=3(x2−1)+15x−30
5x2+3x2+12x+12=3x2−3+15x−30
8x2+12x+12=3x2+15x−33
8x2+12x+12−3x2−15x+33=0
5x2−3x+45=0
Δ=(−3)2−4⋅5⋅45=9−900=−891
Brak rozwiązań.