(2a +3a +4a) (6a -3ab +4a)= 12a² - 6a²b + 8a² +18a² -9a²b +12a² +24a² -12a²b +16a²=
90a² - 27a²b.
(3x² + 4x) (2x +4x - 5x²)= 6x³ + 12x³ - 15x⁴ + 8x² +16x² -20x³ = 24x² +2x³ -15x⁴
(5y+6y) 8= 40y +48y =88y
(6xy +7xy) (7x -8x+ 2xy)= 42x²y-48x²y+12x²y² +49x²y-56x²y+14x²y²= -13x²y +26x²y²
(3x+3x-4x) 6= 18x+18x-24x=-12x
6(2x+5y+10z)=12x+30y+60z
(8a+7b)5=40a+35b
(6a+5b)(8+5)=48a+30a+40b+25b=78a+55b
(7a-8b)(5+7+2)=35a+49a+14a-40b-42b-16b=98a-98b
(8x+9y)(2x+3x+8x)=16x²+24x²+64x²+18xy+27xy+72xy=104x²+117xy