1) 8x + 2x² = 2x · ()
2) 28x² - 4x³ = 4x² · ()
3) 5x²y + 10x²y³ - x²y⁴ = x²y · ( +y²-y³)
4) 12t² - 3t = · (4t - )
5) 75a²b⁴ + 25ab² = ab² · (b² + 1)
6) 3x ·(x²y - y²x) - 5 · (x²y - y²x) = () · (x²y - y²x)
7) a² · (b + 5) + a² · (2b - 5) = a² · [() + (2b - 5)] = a² · ()
8) a · (2x + 1) + b · (2x + 1) + 3c· (2x + 1) = (a + b + 3c) · ()
9) x · (x - 5) + x · (x + 2) = · [(x - 5) + (x + 2)] = x · ()
10 ) 21r⁷s³ - 7r²s³ + 28r⁵s⁷ = r²s³· (r⁵ - + 4r³s⁴)