50-2x^2 = 2(25-x^2) = 2(5+x)(5-x)
ax^2-ay^2 = a(x^2-y^2) = a(x+y)(x-y)
7c^2-14c+7 = 7(c^2-2c+1) = 7(c-1)(c-1) = 7(c-1)^2
5x^2+10xy+5y^2 = 5(x^2+2xy+y^2) = 5(x+y)^2
50-2x^2 = 2(25-x^2) = 2(5+x)(5-x)
ax^2-ay^2 = a(x^2-y^2) = a(x+y)(x-y)
7c^2-14c+7 = 7(c^2-2c+1) = 7(c-1)(c-1) = 7(c-1)^2
5x^2+10xy+5y^2 = 5(x^2+2xy+y^2) = 5(x+y)^2