3. 1)2a+5b=8-15=-7 2)4m-3n+10=-20 3) 5x+2y-3z+7=30-34-21=-24
4) 2ab-3bc-4ac=-16-18-48=-82 5)3x-4y+xy-46=-6+24+12-46=-6
4. 1)a3*a5=a8 2)b7*b2=b9 3)(-m2)*m4=-m6 4) (-x2)*(-x6)=x8 5) y5*(-y6)=-y11
5. 1)(x+2)*5=5x+10 2) 6(3y-4)=18y-24 3) (2m+3n)*7=14m+21n 4)c(2a+5b)=2ac+5bc
5)-4a(3b-2a)=-12ab+8a2
6.1)(x+2)*(x-3)=x2-3x+2x+6=x2-x-6 2)(5x+1)*(2x+4)=10×2+20x+2x+4=10×2+22+4
3)(3b+2)(4-b)=12b-3b2+8-2b=10b-3b2+8
4)(2y-5)(4y-3)=8y2-6y-20y+15=8y2-26y+15
5)(3a+4)(2a-3)=6a2-9a+8a-12=6a2-a-12