4.
[tex]a) \ 15y-10+25x = 5(3y-2+5x)\\\\b) \ 12x^{2}+36y+18 = 6(2x^{2}+6y+3)\\\\c) \ 1\frac{1}{7}x + 2\frac{3}{7}y+\frac{2}{7} = \frac{8}{7}x + \frac{17}{7}y + \frac{2}{7} = \frac{1}{7}(8x+17y+2)[/tex]
