<span>498+(2,7-5х)(6х-7)=(9-0,5х)(60х+1)
498 + 16,2х - 18,9 -30х</span>²<span> +35х = 540х +9 -30х</span>²<span> -0,5х
479,1 + 51,2х = 9 + 539,5х
51,2х - 539,5х= 9 - 479,1
-488,3х = -479,1
х = 479,1: 488,3
х = 4791/4883
</span>
А. да 2,521
Б нет т.к -
В нет т.к 2,(2)
Г нет т.к -
1) 2x^2 - 7x - 9 < 0
2x^2 - 7x - 9 = 0
x1 = - 1 ; x2 =
x ∈ ( - 1 ; 4,5 )
2) 4x^2 - x + 1 > 0
4x^2 - x + 1 = 0
D < 0 => корней нет.
x ∈ R
3) x^2 > 49
x^2 - 49 = 0
x1 = - 7 ; x2 = 7
x ∈ ( - ∞ ; - 7 ) U ( 7 ; + ∞ )
4) (x+3)(x-4)(x-6) < 0
(x+3)(x-4)(x-6) = 0
x1 = - 3 ; x2 = 4 ; x3 = 6
x ∈ ( - ∞ ; - 3 ) U ( 4 ; 6 )
5) 3x^2 + mx + 3 = 0
D = 0
m^2 = 36
m1 = 6 ; m2 = - 6
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