Ответ:
f(-x) = x²+x=2 f(x+2) = x²+3x
Объяснение:
f(x)=x²-x-2
f(-x) = (-x)²-(-x)-2= x²+x=2
f(x+2) = (x+2)²-(x+2) -2=
=x²+4x+4 -x-2-2=
=x²+3x +4-4=x²+3x
√(4-х)=3
ОДЗ: 4-х≥0
x≤4
(√(4-х))²=3²
4-х=9
х=4-9
х=-5 ≤4
Ответ: -5
Пусть 3^х=t
t^2-7t-18=0
t1=-2; t2=9
Первый корень не подойдет, т.к. 3^х>0
Тогда 3^х=9
х=2.
3Х - Y = - 10
3X + 10 = Y
__________
Y^2 = 9X^2 + 60X + 100
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X^2 - 4XY - Y^2 = - 20
X^2 - 4X*( 3X + 10) - ( 9X^2 + 60X + 100) = - 20
X^2 - 12X^2 - 40X - 9X^2 - 60X - 100 + 20 = 0
- 20X^2 - 100X - 80 = 0
- 20 * ( X^2 + 5X + 4 ) = 0
D = 25 - 16 = 9 ; V D = 3
X1 = ( - 5 + 3 ) : 2 = ( - 1 )
X2 = ( - 8 ) : 2 = ( - 4 )
====================
Y = 3X + 10
Y1 = - 3 + 10 = 7
Y2 = - 12 + 10 = ( - 2 )
=====================
Ответ ( - 1 ; 7 ) ; ( - 4 ; - 2 )
============================================================
Y = X - 1
Y = X^2 + 2X - 3
----------------------
X^2 + 2X - 3 = X - 1
X^2 + X - 2 = 0
D = 1 - 4*1*(-2) = 9 ; V D = 3
X1 = ( - 1 + 3 ) : 2 = 1
X2 = ( - 4 ) : 2 = ( - 2 )
---------------------
Y = X - 1
Y1 = 1 - 1 = 0
Y2 = - 2 - 1 = ( - 3 )
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ответ ( 1 ; 0 ) ; ( - 2 ; - 3 )
4 (х-6)=5
4х-24=5
4х=5+24
4х=29
х=29÷4
х=7,25