Question

Помогите решить уравнения! Срочно! Даю 30 баллов

Answer 1

1. (a+1)(a+1)=(a+1)^2

2. (2+y)(y+3)=2y+2•3+y•y+3y=2y+6+y^2+3y=5y+6+y^2=y^2+5y+6

3. (2a+b)(a+2b)=2a•a+2a•28+ab+28b=2a^2+56a+ab+28b

4. (5m+7n)(2n+4m)=5m•2n+5m•4m+7n•2n+7n•4m=10mn+20m^2+14n^2+28mn=38mn+20m^2+14n^2

5. (2x-3y)(3x+5y)=2x•3x+2x•5y-3y•3x-3y•5y=6x^2+10xy-9xy-15y^2=6x^2+xy-15y^2

6. (-a-b)(2a-3b)=-a•2a-a•(-3b)-2ab-b•(-3b)=-2a^2+3ab-2ab+3b^2=-2a^2+ab+3b^2

7. (2x^2-y^2)(y^2+2x^3)=2x^2y^2+2x^2•2x^3-y^2•y^2-2x^3y^2=2x^2y^2+4x^5-y^4-2x^3y^2

8. (2a+3b)(4a^2-6ab+9b^2)=(2a)^3+(3b)^3=8a^3+27b^3