Log(5)(2-x)+0,5log(5)(4x-11)=0
{2-x>0⇒x<2
{4x-11≠0⇒x≠2,75
x∈(-∞;2)
log(5)(2-x)+log(5)√(4x-11)²=0
log(5)(2-x)+log(5)|4x-11|=0
log(5)[(2-x)*|4x-11|]=0
(2-x)*|4x-11|=1
x∈(-∞;2)⇒|4x-11|=11-4x
(2-x)(11-4x)=0
x=2не удов усл
х=2,75 не удов усл
Ответ нет решения
lgx²+lg(x+4)²≥-lg1/9
{x≠0
{x≠-4
x∈(-∞;-4) U (-4;0) U (0;∞)
lg[x²(x+4)²]≥lg9
x²(x+4)²≥9
x²(x+4)²-9≥0
(x(x+4)-3)(x(x+4)+3)≥0
(x²+4x-3)(x²+4x+3)≥0
x²+4x-3=0
D=16+12=28
x1=(-4-2√7)/2=-2-√7 U x2=-2+√7
x²+4x+3=0
x1+x2=-4 U x1*x2=3⇒x1=-3 U x2=-1
+ _ + _ +
-------------[-2-√7]------(-4)-------[-3]------------[-1]------(0)--------[-2+√7]--------------
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x∈(-∞;-2-√7] U [-3;-1] U [-2+√7;∞)
3х+х=340
х=340/4
х=85
3х=85*3=255
Ответ:
Объяснение:
2(y+1)=3x-4 , 2y+2=3x-4, 2y-3x=-6, (1), 5x+y=3x+11, y=3x+11-5x, y=-2x+11 (2), (2)-e подставляем в (1), 2(-2x+11)-3x=-6, -4x+22-3x=-6, -7x=-28, x=4,
y=-2*4+11=3, ответ: (4;3)