№ 4
f(x) = 1/x + x² ; g(x) = 2/x - 8
a) f(-1) = -1 +1 = 0
g(-1) = -2 -8 = -10
g(3) = 2/3 - 8 = -22/3
0 -10 -22/3 = -10 - 7 1/3 = -17 1/3
б) f(0,5) = 2 + 0,25 = 2,25
g(2) = 1 - 8 = -7
f(0,5) - 3g(2) = 2,25 -3*(-7) = 23,25
в) f(-2) = -1/2 + 4 = 3,5
g(0,5) = 1 - 8 = -7
4f(-2) - g(0,5) = 4*3,5 +7 = 14 +7 = 21
г) f(1/4) = 4 + 1/16 = 4 1/16
g(-2/5) = -5 - 8 = -13
16f(1/4) + 2g(-2/5) = 16*65/16 + 2*(-13) = 65 -26 = 39
№5
f(x) = x² + 5x -1
a) x² + 5x -1= -1
х² +5х = 0
х = 0 и -5
б)x² + 5x -1 = 5
х² + 5х -6=0
х = -6 и 1
в)x² + 5x -1 = -5
х² + 5х +4 = 0
х = -4 и -1
г)x² + 5x -1 = -6,25
х² + 5х + 5,25= 0
х = -7/2 и --3/2
1
x≠-2,x≠-5
(x-3)(x+5)=(3x-7)(x+2)
x²+5x-3x-15-3x²-6x+7x+14=0
-2x²+3x-1=0
2x²-3x+1=0
D=9-8=1
x1=(3-1)/4=0,5
x2=(3+1)/4=2
2
x≠0
3x²-7x+4=0
D=49-48=1
x1=(7-1)/6=1
x2=(7+1)/6=4 1/3
3
x≠-4
(3x+1)*(x+4)=20
3x²+12x+x+4-20=0
3x²+13x-16=0
D=169+192=361
x1=(-13+19)/6=-1
x2=(-13-19)/6=-5 1/3
4
x≠0;x≠-1
4(x+1)+10*x=3x(x+1)
3x²+3x-4x-4-10x=0
3x²-11x-4=0
D=121+48=169
x1=(11-13)/6=-1/3
x2=(11+13)/6=4
A)y^2-6y=0
y(y-6)=0
y=0 или y-6=0
y=6
а^6 - 3а^4 b^2 + 3a^4 b^2 - b^6
стрелочки вверх - это степень