a) \(A=5\left(x-y\right)+ax-ay=\left(a+5\right)\left(x-y\right)\)
b) \(B=a\left(x+y\right)-4x-4y=\left(x+y\right)\left(a-4\right)\)
c) \(C=xz+yz-5\left(x+y\right)=\left(x+y\right)\left(z-5\right)\)
d) \(D=a\left(x-y\right)+bx-by=\left(a+b\right)\left(x-y\right)\)
e) \(E=x\left(x+y\right)-5x-5y=\left(x-5\right)\left(x+y\right)\)
f) \(F=x^2-x-y^2-y=\left(x-y\right)\left(x+y\right)-\left(x+y\right)=\left(x+y\right)\left(x-y-1\right)\)
g) \(G=x^2-xy+x-y=x\left(x-y\right)+x-y=\left(x+1\right)\left(x-y\right)\)
A = 5(x - y) + ax - ay = 5(x - y) + a(x - y) = (a + 5)(x - y)
B = a(x + y) - 4x - 4y = a(x + y) - 4(x + y) = (a - 4)(x + y)
C = xz + yz - 5(x + y) = z(x + y) - 5(x + y) = (z - 5)(x + y)
D = a(x - y) + bx - by = a(x - y) + b(x - y) = (a + b)(x - y)
E = x(x + y) - 5x - 5y = x(x + y) - 5(x + y) = (x - 5)(x + y)
F = x2 - x - y2 - y = (x2 - y2) - (x + y) = (x2 - xy + xy - y2) - (x + y) = [x(x - y) + y(x - y)] - (x + y) = (x - y)(x + y) - (x + y) = (x + y)(x - y - 1)
G = x2 - xy + x - y = x(x - y) + (x - y) = (x + 1)(x - y)
A = 5( x - y ) + ax - ay
= 5( x - y ) + a( x - y )
= ( x - y )( 5 + a )
B = a( x + y ) - 4x - 4y
= a( x + y ) - 4( x + y )
= ( x + y )( a - 4 )
C = xz + yz - 5( x + y )
= z( x + y ) - 5( x + y )
= ( x + y )( z - 5 )
D = a( x - y ) + bx - by
= a( x - y ) + b( x - y )
= ( x - y )( a + b )
E = x( x + y ) - 5x - 5y
= x( x + y ) - 5( x + y )
= ( x + y )( x - 5 )
F = x2 - x - y2 - y
= ( x2 - y2 ) - ( x + y )
= ( x - y )( x + y ) - ( x + y )
= ( x + y )( x - y - 1 )
G = x2 - xy + x - y
= x( x - y ) + ( x - y )
= ( x - y )( x + 1 )
Bài làm :
A = 5( x - y ) + ax - ay
= 5( x - y ) + a( x - y )
= ( x - y )( 5 + a )
B = a( x + y ) - 4x - 4y
= a( x + y ) - 4( x + y )
= ( x + y )( a - 4 )
C = xz + yz - 5( x + y )
= z( x + y ) - 5( x + y )
= ( x + y )( z - 5 )
D = a( x - y ) + bx - by
= a( x - y ) + b( x - y )
= ( x - y )( a + b )
E = x( x + y ) - 5x - 5y
= x( x + y ) - 5( x + y )
= ( x + y )( x - 5 )
F = x2 - x - y2 - y
= ( x2 - y2 ) - ( x + y )
= ( x - y )( x + y ) - ( x + y )
= ( x + y )( x - y - 1 )
G = x2 - xy + x - y
= x( x - y ) + ( x - y )
= ( x - y )( x + 1 )