Помогите 7 класс алгебра 30 балов дам
1)3b+bc+3ac+9a
2)a $a^{2} y^{2} - x^{6}$
3) $a^{3} - a^{2} b+3ac+9a$
4) $x^{2} - b^{2} -ax-ab$
5) $c^{2} -4c+4- 9^{2}$
6) $4c^{2} +20c+25- 9a^{2}$
7) $y^{2} x+y+y x^{2} +x+4yx+4$
8) $y^{2} x+y+y x^{2} +x+4yx+4$
9) $x^{2} +x-xy- y^{2} + y^{3} -x y^{2}$

1) $3b+bc+3ac+9a=b(3+c)+3a(c+3)=(c+3)(b+3a);$

2) $a^{2}y^{2}-x^{6}=(ay)^{2}-(x^{3})^2=(ay-x^{3})(ay+x^{3});$

3) $a^{3}-a^{2}b+3ac+9a=a(a^{2}-ab+3c+9)$

4) $x^{2}-b^{2}-ax-ab=(x-b)(x+b)-a(x+b)=(x+b)(x-b-a);$

5) $c^2-4c+4-9x^2=c^2-2cdot2c+2^2-(3x)^2=(c-2)^2-(3x)^2==(c-2-3x)(c-2+3x);$

6) $4c^2+20c+25-9a^2=(2c)^2+2cdot2ccdot5+5^2-(3a)^2==(2c+5)^2-(3a)^2=(2c+5-3a)(2c+5+3a);$

7) $y^{2}x+y+yx^{2}+x+4yx+4=y(yx+1)+x(yx+1)+4(yx+1)==(yx+1)(y+x+4);$

9) $x^2+x-xy-y^2+y^3-xy^2=x(x+1-y)-y^2(1-y+x)==(x+1-y)(x-y^2).$