[tex]a) \ 2x(3x+5)+3(x^{2}-3x+2) = 6x^{2}+10x + 3x^{2}-9x+6 = 9x^{2}+x+6\\\\b) \ 3(2x^{2}+x-7)-2x(x-3) = 6x^{2}+3x-21-2x^{2}+6x = 4x^{2}+9x-21[/tex]
