c: =(x-5)(x+2)

a: \(=xy\left(5x-1\right)\)

b: \(=\left(x-2\right)\left(3x-5\right)\)

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

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

c) \(=3x\left(x-y\right)+5\left(x-y\right)=\left(x-y\right)\left(3x+5\right)\)

d) \(=\left(x+y\right)^2-25=\left(x+y-5\right)\left(x+y+5\right)\)

e) \(=x\left(x^2-11x+30\right)\)

f) \(=x\left(x-3\right)+6\left(x-3\right)=\left(x-3\right)\left(x+6\right)\)

\(P=3^2-5\cdot3-3\cdot1-5\cdot\left(-1\right)=9-15-3+5=-9+5=-4\)

\(x^2+xy-5x-5y=\left(x^2+xy\right)-\left(5x+5y\right)\)

\(=x\left(x+y\right)-5\left(x+y\right)=\left(x-5\right)\left(x+y\right)\)

x(x+y)-5(x+y) = (x-5)(x+y) bài này mik hok qua rùi mik đang ôn tập nên là mik tự làm chứ ko chép mấy câu trả lời khác

A = x 2 – 5x + xy – 5y = ( x 2 + xy) – (5x + 5y) = x(x + y) – 5(x + y)

= (x – 5)(x + y)

Tại x = -5; y = -8 ta có

A = (-5 – 5)(-5 – 8) = (-10)(-13) = 130

Đáp án cần chọn là: A

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

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

b) \(3x^2-3xy-5x+5y=\left(3x^2-3xy\right)-\left(5x-5y\right)\)

\(=3x\left(x-y\right)-5\left(x-y\right)=\left(3x-5\right)\left(x-y\right)\)

a/

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

b/

\(x^2-5x+xy-5y=x\left(x+y\right)-5\left(x+y\right)=\)

\(=\left(x+y\right)\left(x-5\right)\)