<span> a)(2x-3) (4x+1)=8x^2+2x-12x-3=8x^2-10x-3</span>
5.5^2-0.3*5.15+0.15^2=26.5225-0.3*5.15+0.0225=26.5225-1.545+0.0225=24.5225+0.0225=25
300*130% = 300*1,3 = 390рублей