1 (20 + 10) × 4 =120 (з.)
2 120 : 20 = 6 (д.)
Ответ:
x(1) = 1
x(2) = 2
x(3;4) = (3+-√33) / 2
Объяснение:
(x²-3x)(x²-3x-4)=12
x²-3x=t
t(t-4) = 12
t² - 4t -12 = 0
D = 16 + 48 = 64 = 8²
t(1) = (4-8)/2 = -4/2= -2
t(2) = (4+8) / 2 = 6
x²-3x=-2 x²-3x=6
x²-3x+2 = 0 x²-3x-6=0
D = 9-8 = 1 = 1² D = 9 + 24 = 33 = (√33)²
x(1) = (3+1) / 2 = 2 x(3;4) = (3+-√33) / 2
x(2) = (3-1) / 2 = 1
<span>(х²-5)²-2(х²-5)-8=0
</span>х²-5⇒у у²-2у-8=0 D=4+32=6² у₁=(2+6)/2=4 у₂=(2-6)/2=-2
х²-5-4=0 х²=9 х₁=3 х₂=-3
х²-5+2=0 х²=3 х₃=√3 х₄=-√3