Giúp em chữa bài kiểm tra.

[chuotvip]

ai giup em lam bai kiem tra mot tiet nay voi. hom kiem tra minh chua lam duoc uc lam. ai giai ho minh cai nha
Cau1: Phan Tich Da Thuc Thanh Nhan Tu
a, X[SUB2]2[/SUB2]-X-42
b, X[SUB2]5[/SUB2]+X+1
Cau2: tim gia tri cua X,Y,Z thoa man
X[SUB2]2[/SUB2]+Y[SUB2]2[/SUB2]+Z[SUB2]2[/SUB2]=XY+3Y+2X-4
Cau3:
a, Cho hinh vuong ABCD goi M,N thu tu la trung diem cua Ab va CD. E la mot diem bat ki tren tia doi BC, EM giao ac tai I
Chung minh Mn la tia phan giac cua goc INE
b, Cho tam giac ABC can tai A ,duong cao AH, tu H ke HE vuong voi AC tai E goi M la trung diem cua EH.
Chung minh Am vuong goc voi BE
:sweat::sweat::sweat::sweat::sweat:

 

[Thandieu2]

ai giup em lam bai kiem tra mot tiet nay voi. hom kiem tra minh chua lam duoc uc lam. ai giai ho minh cai nha
Cau1: Phan Tich Da Thuc Thanh Nhan Tu
a, X[SUB2]2[/SUB2]-X-42
b, X[SUB2]5[/SUB2]+X+1
Cau2: tim gia tri cua X,Y,Z thoa man
X[SUB2]x[/SUB2]+Y[SUB2]2[/SUB2]+Z[SUB2]2[/SUB2]=XY+3Y+2X-4
Cau3:
a, Cho hinh vuong ABCD goi M,N thu tu la trung diem cua Ab va CD. E la mot diem bat ki tren tia doi BC, EM giao ac tai I
Chung minh Mn la tia phan giac cua goc INE
b, Cho tam giac ABC can tai A ,duong cao AH, tu H ke HE vuong voi AC tai E goi M la trung diem cua EH.
Chung minh Am vuong goc voi BE
:sweat::sweat::sweat::sweat::sweat:

Em chú ý viết tiếng Việt có dấu nhé.

Bài 1:
a) \[x^2 + x + 42\]
\[= x^2 + 6x - 7x + 42\]
\[= x(x + 6) - 7( x + 6)\]
\[= (x - 7)(x+6)\]

b) \[x^5 + x + 1\]
\[= x^5 - x^2 + (x^2 + x + 1)\]
\[= x^2(x^3 - 1) + (x^2 + x + 1)\]
\[= x^2(x-1)(x^2 + x + 1) + (x^2 + x + 1)\]
\[= (x^2 + x + 1)[x^2(x-1) + 1]\]

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