А) (m+2)²=m²+2*m*2+2²=m²+2m+4
б) (2a+5x)²=(2a)²+2*2a*5x+(5x)²=4a²+20x+25x²
в) (3+a²)²=3²+2*3*a²+(a²)²=9+6a²+a⁴
г) (x-1)²=x²-2*x*1+1²=x²-2x+1
д) (2c-a)²=(2c)²-2*2c*a+a²=4c²-4ac+a²
е) (5-x²)²=5²-2*5*x²+(x²)²=25-10x²+x⁴
ё) (1-ab)²=1²-2*1*ab+(ab)²=1-2ab+a²b²
ж) (cq-2p)²=(cq)²-2*cq*2p+(2p)²=c²q²-4cpq+4p²