Question

20-(2x-3)²≥5(x+1)²-(3x-4)²

Answer 1

20-(2x-3)²≥5(x+1)²-(3x-4)²
20-4x²+12x-9≥5x²+10x+5-9x²+24x-16
-4x²+12x+11≥-4x²+34x-11
-4x²+4x²+12x-34x+11+11≥0
-22x+22≥0
22(-x+1)≥0
-x+1≥0
-x≥-1
x≤1
x∈(-α, 1]

Answer 2

$20-4x^2+12x-9\geq5x^2+10x+5-9x^2+24x-16$
Separam si reducem termenii asemenea
$-22x\geq-22\Rightarrow x\leq1\Rightarrow x\in (-\infty;1]$