Odpowiedź:
a)(-3c+2d)(2c-6) = -6c²+18c+4cd-12d
b) (-10m+3n)(5n-4) = -50mn+40m+15n²-12n
c)(9s-2t)(7t-s) = 63st-9s²-14t²+2st = -9s²+65st-14t²
d)(3a+5b)(2a+7b) = 6a²+21ab+10ab+35b² = 6a²+31ab+35b²
e)(4m-3n)(5m-n) = 20m²-4mn-15mn+3n² = 20m²-19mn+3n²
f)(-3x-5y)(2x+4y) = -6x²-12xy-10xy-20y² = -6x²-22xy-20y²