4с^2+12с+9 81х^2+18ху+у^2

Question

4с^2+12с+9 81х^2+18ху+у^2

Answer 1

4c^2+12c+9=4c^2+6c+6c+9=2c(2c+3)+3(2c+3)=(2c+3)(2c+3)=(2c+3)^2                           81x^2+18xy+y^2=(9x+y)^2