Câu hỏi của Han Yujin

Question

a)G=(7 -x)^2 + 2(x-7) (x+3) + (x+3)^2b) H =9x^2 + 6x(x-5) + (x-5)^2giúp mình

Nguyễn Lê Phước Thịnh · Accepted Answer

a: $G=\left(7-x\right)^2+2\left(x-7\right)\left(x+3\right)+\left(x+3\right)^2$ $=\left(x-7\right)^2+2\left(x-7\right)\left(x+3\right)+\left(x+3\right)^2$ $=\left(x-7+x+3\right)^2=\left(2x-4\right)^2=4x^2-16x+16$ b: $H=9x^2+6x\left(x-5\right)+\left(x-5\right)^2$ $=\left(3x\right)^2+2\cdot3x\cdot\left(x-5\right)+\left(x-5\right)^2$ $=\left(3x+x-5\right)^2=\left(4x-5\right)^2=16x^2-40x+25$Câu trả lời: a: $G=\left(7-x\right)^2+2\left(x-7\right)\left(x+3\right)+\left(x+3\right)^2$ $=\left(x-7\right)^2+2\left(x-7\right)\left(x+3\right)+\left(x+3\right)^2$ $=\left(x-7+x+3\right)^2=\left(2x-4\right)^2=4x^2-16x+16$ b: $H=9x^2+6x\left(x-5\right)+\left(x-5\right)^2$ $=\left(3x\right)^2+2\cdot3x\cdot\left(x-5\right)+\left(x-5\right)^2$ $=\left(3x+x-5\right)^2=\left(4x-5\right)^2=16x^2-40x+25$

idkyourName · Answer

a: 
G
=
(
7
−
x
)
2
+
2
(
x
−
7
)
(
x
+
3
)
+
(
x
+
3
)
2

=
(
x
−
7
)
2
+
2
(
x
−
7
)
(
x
+
3
)
+
(
x
+
3
)
2

=
(
x
−
7
+
x
+
3
)
2
=
(
2
x
−
4
)
2
=
4
x
2
−
16
x
+
16

b: 
H
=
9
x
2
+
6
x
(
x
−
5
)
+
(
x
−
5
)
2

=
(
3
x
)
2
+
2
⋅
3
x
⋅
(
x
−
5
)
+
(
x
−
5
)
2

=
(
3
x
+
x
−
5
)
2
=
(
4
x
−
5
)
2
=
16
x
2
−
40
x
+
25Câu trả lời: a: 
G
=
(
7
−
x
)
2
+
2
(
x
−
7
)
(
x
+
3
)
+
(
x
+
3
)
2

=
(
x
−
7
)
2
+
2
(
x
−
7
)
(
x
+
3
)
+
(
x
+
3
)
2

=
(
x
−
7
+
x
+
3
)
2
=
(
2
x
−
4
)
2
=
4
x
2
−
16
x
+
16

b: 
H
=
9
x
2
+
6
x
(
x
−
5
)
+
(
x
−
5
)
2

=
(
3
x
)
2
+
2
⋅
3
x
⋅
(
x
−
5
)
+
(
x
−
5
)
2

=
(
3
x
+
x
−
5
)
2
=
(
4
x
−
5
)
2
=
16
x
2
−
40
x
+
25

Khoá học trên OLM (olm.vn)

Khoá học trên OLM (olm.vn)