(a-2b)(b+4a)-7b(a+b)=ab+4a²-2b²-2ab-7ab-7b²=4a²-9b²-8ab
<span>(p-q)(p+3q)-(p^2+3q^2)=p</span>²-qp+3pq-3q²-p²-3q²=-6q²+2qp
<span>(2x -3)^2-3x+2=0
4х</span>²-12х+9-3х+2=0
4х²-15х+11=0
Д=в²-4ас=225 - 4*4*11=225-176=49
х1=15+7/8=22/8
х2=15-7/8=8/8=1
А) 16 + 8a + a² = (4+a)²
б) 4a² + 12ab + 9b² = (2a+3b)²
в) x² - 14x + 49 = (x-7)²
г) x² + 12x + 36 = (x+6)²
д) 49b² - 28ab + 4a² = (7b-2a)²