1) 14x+21y= ? 2) mx+my+6x+6y= ? 3) a²+12a+36= ? 4) b²+4a²-4ab= ? 5) 25x²-y²= ? 6) 16x²-4= ?

14х+21у=7(2х+3у)mx+my+6x+6y=m(x+y)+6(x+y)a^2+12a+36=a^2+2a+6^2=(a+6)^2b^2+4a^2-4ab=b^2-4ab+4a^2=(b-2a)^225x^2-y^2=5^2×x^2=(5x)^2-y^2=(5x-y)(5x+y)16x^2-4=4(4x-1)=4(2x-1)(2x+1)