resolver cada producto 1.(x-2)(x+1) 2.(a+3)(a-2) 3.(2a-3)(a+3) 4.(4x+2)(x-5) 5.(5x-2)(5x-2) 6.(3x+2)(3x-2) 7.(4a-b)(3a+b) 8.(2x+5y)(5x+y) 9.(2x2-1)(3x2-3) 10.(x-3)3 11.(7a2-b)(3a-2b) 12.(a+2)3​