\(=\left(a+b\right)\left(x+1\right)\)

\(b,=a\left(x+y\right)+2\left(x+y\right)=\left(a+2\right)\left(x+y\right)\\ c,=x\left(x+y\right)-2\left(x+y\right)=\left(x-2\right)\left(x+y\right)\\ d,=5a\left(2x-y\right)-\left(2x-y\right)=\left(5a-1\right)\left(2x-y\right)\)

1) x - y - a(x - y) = (x - y) - a(x - y) = (1 - x)(x - y)

2) a - b + x(a - b) = (a - b) + x(a - b) = (1 + x)(a - b)

3) a(x - y) - x + y = a(x - y) - (x - y) = (a - 1)(x - y)

4) x(a - b) - a + b = x(a - b) - (a - b) = (x - 1)(a - b)

5) ax + ay + bx + by = a(x + y) + b(x + y) = (a + b)(x + y)

6) ax + ay - bx - by = a(x + y) - b(x + y) = (a - b)(x + y)

7) - 2x - 2y + ax + ay = -2(x + y) + a(x + y) = (a - 2)(x + y)

8) x² - xy - 2x + 2y = x(x - y) - 2(x - y) = (x - 2)(x - y)

Sorry nha, giờ mình chỉ rảnh làm 8 câu thôi

bn post nhiều nên mình ghi đáp án thôi nhé phần nào sai đề mình cho qua

b)\(\left(x+1\right)\left(xy+1\right)\)

c)\(\left(a+b\right)\left(x+y\right)\)

d)\(\left(x-a\right)\left(x-b\right)\)

e)\(\left(x+y\right)\left(xy-1\right)\)

f)\(\left(a-b\right)\left(x^2+y\right)\)

\(1,ax+ay+bx+by\)

\(=\left(ax+ay\right)+\left(bx+by\right)\)

\(=a\left(x+y\right)+b\left(x+y\right)\)

\(=\left(x+y\right)\left(a+b\right)\)

\(2,ax+ay+2x+2y\)

\(=\left(ax+ay\right)+\left(2x+2y\right)\)

\(=a\left(x+y\right)+2\left(x+y\right)\)

\(=\left(x+y\right)\left(a+2\right)\)

\(3,ax+ay-bx-by\)

\(=\left(ax+ay\right)-\left(bx+by\right)\)

\(=a\left(x+y\right)-b\left(x+y\right)\)

\(=\left(x+y\right)\left(a-b\right)\)

\(4,ax+ay-2x-2y\)

\(=\left(ax+ay\right)-\left(2x+2y\right)\)

\(=a\left(x+y\right)-2\left(x+y\right)\)

\(=\left(x+y\right)\left(a-2\right)\)

ax + ay + bx + by

= a.(x+y) + b.(x+y)

= (x+y).(a+b)

ax + ay + 2x + 2y

= a.(x+y) + 2.(x+y)

= (x+y).(a+2)

ax + ay - bx - by

= a.(x+y) - b.(x+y)

= (x+y).(a-b)

ax + ay - 2x - 2y

= a.(x+y) - 2.(x+y)

= (x+y).(a-2)

Ta có: \(\left(ax+by\right)^2=\left(a^2+b^2\right)\left(x^2+y^2\right)\)

\(\Leftrightarrow a^2x^2+2abxy+b^2y^2=a^2x^2+a^2y^2+x^2b^2+b^2y^2\)

\(\Leftrightarrow2abxy=a^2y^2+x^2b^2\)

\(\Leftrightarrow\left(ay-xb\right)^2=0\)

\(\Leftrightarrow ay=xb\)

hay \(\dfrac{a}{x}=\dfrac{b}{y}\)

\(a,xy+1-x-y\)

\(=\left(xy-y\right)+\left(1-x\right)\)

\(=y\left(x-1\right)- \left(x-1\right)\)

\(=\left(x-1\right)\left(y-1\right)\)

\(b,ax+ay-3x-3y\)

\(=a\left(x+y\right)-3\left(x+y\right)\)

\(=\left(x+y\right)\left(a-3\right)\)

\(c,x^3-2x^2+2x-4\)

\(=x^2\left(x-2\right)+2\left(x-2\right)\)

\(=\left(x^2+2\right)\left(x-2\right)\)

\(d,x^2+ab+ax+bx\)

\(=\left(x^2+ax\right)+\left(ab+bx\right)\)

\(=x\left(a+x\right)+b\left(a+x\right)\)

\(=\left(a+x\right)\left(b+x\right)\)

\(e,16-x^2+2xy-y^2\)

\(=4^2-\left(x^2-2xy+y^2\right)\)

\(=4^2-\left(x-y\right)^2\)

\(=\left(4-x+y\right)\left(4+x-y\right)\)

\(f,ax^2+ax-bx^2-bx-a+b\)

\(=\left(ax^2-bx^2\right)+\left(ax-bx\right)-\left(a-b\right)\)

\(=x^2\left(a-b\right)+x\left(a-b\right)-\left(a-b\right)\)

\(=\left(a-b\right)\left(x^2+x-1\right)\)

d) ax² + ay - bx² - by

= ( ax² + ay ) - ( bx² + by )

= a ( x² + y ) - b ( x² + y )

=  ( x² + y )( a - b )

c) x²y + xy² - x - y

= ( x²y + xy² ) - ( x + y )

= xy ( x + y ) - ( x+ y )

= ( x + y ) ( xy - 1 )

b) ax + by + ay + bx

= ax + ay + bx + by

= a ( x + y ) + b ( x + y )

= ( x + y ) ( a + b )

a) \(xy+1-x-y\)

\(=x\left(y-1\right)-\left(y-1\right)\)

\(=\left(y-1\right)\left(x-1\right)\)

b) \(ax+ay-3x-3y\)

\(=a\left(x+y\right)-3\left(x+y\right)\)

\(=\left(x+y\right)\left(a-3\right)\)

c) \(x^3-2x^2+2x-4\)

\(=x^2\left(x-2\right)+2\left(x-2\right)\)

\(=\left(x-2\right)\left(x^2+2\right)\)

d) \(x^2+ab+ax+bx\)

\(=x\left(b+x\right)+a\left(b+x\right)\)

\(=\left(b+x\right)\left(a+x\right)\)

e) \(16-x^2+2xy-y^2\)

\(=16-\left(x^2-2xy+y^2\right)\)

\(=4^2-\left(x-y\right)^2\)

\(=\left(4-x+y\right)\left(4+x-y\right)\)

f) \(ax^2+ax-bx^2-bx-a+b\)

\(=\left(ax^2+ax-a\right)-\left(bx^2+bx-b\right)\)

\(=a\left(x^2+x-1\right)-b\left(x^2+x-1\right)\)

\(=\left(x^2+x-1\right)\left(a-b\right)\)

a) \(xy+1-x-y=\left(xy-x\right)+\left(1-y\right)=x\left(y-1\right)+\left(1-y\right)=x\left(y-1\right)-\left(y-1\right)=\left(x-1\right)\left(y-1\right)\)

b) \(ax+ay-3x-3y=a\left(x+y\right)-3\left(x-y\right)=\left(a-3\right)\left(x+y\right)\)

c) \(x^3-2x^2+2x-4=x^2\left(x-2\right)+2\left(x-2\right)=\left(x^2+2\right)\left(x-2\right)\)

d) \(x^2+ab+ax+bx=\left(x^2+ax\right)+\left(ab+bx\right)=x\left(x+a\right)+b\left(a+x\right)=\left(x+b\right)\left(x+a\right)\)

e) \(16-x^2+2xy-y^2=16-\left(x-y\right)^2=\left(4-x+y\right)\left(4+x-y\right)\)

f) \(ax^2+ax-bx^2-bx-a+b=\left(a-b\right)x^2+\left(a-b\right)x-a+b=\left(a-b\right)\left(x^2+x-1\right)\)