1) 25x^2 - 5x^2 = (5x)^2
2) 16m^4 n^2 = (4m^2 n)^2
3) 0.09c^6 = (0.3c^3)^2
4) 1.21y^8 = (1.1y^4)^2
5)
6) 4k^2n^2 = (2kn)^2
7) 100t^6 = (10t^3)^2
8)
9) a^6b^12c^4 = (a^3b^6c^2)^2
10) 0.64x^2y^2c^2 = (0.8xyc)^2
11) 400m^2s^6 = (20ms^3)^2
12)
13) 0.0016k^2c^8y^2 = (0.04kc^4y)^2
14) 9p^2n = (3p∙n^{1/2})^2
15) 1.44a^4n = (1.2a^2∙n^{1/2})^2