Toán Lớp 8: bài 1 2a+2b 6xy-12x-18y -2ax-4ay -2a ²b-4ab ²-6ab bài 2 x(x-a)+x-a a(x+y)-x-y ã+ay+2x+2y x ²-xy-2x+2y

Question

Toán Lớp 8:  bài 1 2a+2b 6xy-12x-18y -2ax-4ay -2a ²b-4ab ²-6ab bài 2 x(x-a)+x-a a(x+y)-x-y ã+ay+2x+2y x ²-xy-2x+2y

daolanhoa · Answer

B1
A)2a+2b
=2(a+b)
B)6xy- 12x- 18y
= 3xy(2-4y-6x)
C)-2ax-4ay
= 2axy(1-2)
D)-2a²b- 4ab²-6ab
= 2ab(a-2b-3)
B2
A)x(x-a)+x-a
= x(x-a)+(x-a)
=(x-a)(x+1)
B)a(x+y)-x-y
= a(x+y)-(x+y)
=(x+y)(a-1)
C)ax +ay +2x+2y
= a(x+y)+2(x+y)
=(x+y)(a+2)
D)x²-xy‐2x+2y
=-x(x+y)-2(x+y)
=(x+y)(-x -2)
Bạn than khảo nha

phuongthuydung · Answer

B&agrave;i 1:    a)2a+2b   =2.a+2.b   =2(a+b)   b)6xy-12x-18y   =6.xy-6.2x-6.3y   =6(xy-2x-3y)   c)-2ax-4ay   =-2a.x-2a.2y   =-2a(x+2y)   d)-2a&sup2;b-4ab&sup2;-6ab   =-2ab.a-2ab.2b-2ab.3   =-2ab(a+2b+3)    B&agrave;i 2:    a)x(x-a)+x-a   =x(x-a)+(x-a)   =(x-a)(x+1)   b)a(x+y)-x-y   =a(x+y)-(x+y)   =(x+y)(a-1)   c)ax+ay+2x+2y   =(ax+ay)+(2x+2y)   =a(x+y)+2(x+y)   =(x+y)(a+2)   d)x&sup2;-xy-2x+2y   =(x&sup2;-xy)-(2x-2y)   =x(x-y)-2(x-y)   =(x-y)(x-2)