ê báo cáo ༺ღ¹⁷⁰⁶²⁰¹⁰H𝚘̷àทջ✎﹏ᑭh𝚘̷ทջღ²ᵏ¹⁰༻ღteamღVTP & ❖𝕥𝔢𝔞𝕞 đạ𝔦 𝔟àⓝℊ`✔ & TΣΔM...??? ツ nó láo lắm với lại báo cáo con Dương Hoài Giang nữa 2 bọn nó láo lắm

Ta có

\(B=x^2+2x+y^2-2y-2xy+38\)

\(\Rightarrow B=\left(x^2-2xy+y^2\right)+\left(2x-2y\right)+37\)

\(\Rightarrow B=\left(x-y\right)^2-2\left(x-y\right)+37\)

\(\Rightarrow B=7^2-2.7+37\)

\(\Rightarrow B=49-14+37\)

\(\Rightarrow B=72\)

\(B=x\left(x+2\right)+y\left(y-2\right)-2xy+37\)

\(=x^2+2x+y^2-2y-2xy+37\)

\(=\left(x^2+y^2-2xy+1+2x-2y\right)+36\)

\(=\left(x-y+1\right)^2+36\)

\(=\left(7+1\right)^2+36\)

\(=64+36\)

\(=100\)

\(A=x\left(x+2\right)+y\left(y-2\right)-2xy+37\)

\(=x^2+2x+y^2-2y-2xy+37\)

\(=\left(x^2+y^2-2xy\right)+\left(2x-2y\right)+37\)

\(=\left(x-y\right)^2+2\left(x-y\right)+37\)

Thay \(x-y=7\)vào biểu thức, ta có:

\(A=7^2+2.7+37\)

\(=49+14+37\)

\(=100\)

A= X(X-2)+Y(Y-2) -2XY+37

= X²-2X+Y²-2Y -2XY +37

=(X²-2XY+Y²)+(2X-2Y)+37

=(X-Y)²+2(X-Y)+37

Thế số vào là xong :) :)

a) P = \(x^2+3x+y^2-3y-2xy+90\)

= \(\left(x-y\right)^2+3\left(x-y\right)+90\)

= \(5^2+3.5+90=130\)

b) P = \(4x^2+9y^2-12xy-12x+24xy-18y+118\)

= \(4x^2+9y^2+12xy-12x-18y+118\)

= \(\left(2x+3y\right)^2-6\left(2x+3y\right)+118\)

= \(\left(-7\right)^2-6.\left(-7\right)+118=209\)

Các bạn ơi cho tui hỏi câu này : noise in / kept / night / the / awake / city / at / the / him / .

Giúp mình với , cảm ơn.

a) \(P=x\left(x+3\right)+y\left(y-3\right)-2xy+90\\ P=x^2+3x+y^2-3y-2xy+90\\ P=\left(x^2+y^2-2xy\right)+\left(3x-3y\right)+90\\ P=\left(x-y\right)^2+3\left(x-y\right)+90\\ P=5^2+3.5+90\\ P=130\)

b) \(P=\left(2x-3y\right)^2-12x\left(1-2y\right)-18y+118\\ P=4x^2-12xy+9y^2-12x+24xy-18y+118\\ P=\left(4x^2+12xy+9y^2\right)-6\left(2x+3y\right)+118\\ P=\left(2x+3y\right)^2-6\left(2x+3y\right)+118\\ P=\left(-7\right)^2-6.\left(-7\right)+118\\ P=49+42+118=209\)

Ta có:

A=x²+2x+y²-2y-2xy+37

 =(x²-2xy+y²)+(2x-2y)+37

 =(x-y)²+2(x-y)+1+36

 =(x-y+1)²+36

 =(7+1)²+36

 =64+38

 =100

tích đúng mình làm cho

là sao ạk
giải giùm mình với ạk

1/Ta có: \(A=x\left(x+2\right)+y\left(y-2\right)-2xy+37\)

\(=x^2+2x+y^2-2y-2xy+37\)

\(=\left(x^2-2xy+y^2\right)+\left(2x-2y\right)+37\)

\(=\left(x-y\right)^2+2\left(x-y\right)+37\)

Thay x-y=7 vào A ta đc:

\(A=7^2+2.7+37=49+14+37=100\)

2/Ta có :\(B=x^2+4y^2-2x+10+4xy-4y\)

\(=\left(x^2+4xy+4y^2\right)-\left(2x+4y\right)+10\)

\(=\left(x+2y\right)^2-2\left(x+2y\right)+10\)

Thay x+2y=5 vào B ta đc

\(B=5^2-2.5+10=25-10+10=25\)

\(A=x^2+2x+y^2-2y-2xy+37\)

\(A=x^2-2xy+y^2+2x-2y+37\)

\(A=\left(x-y\right)^2+2\left(x-y\right)+37\)

Thay x-y = 7 ta được:

\(A=7^2+2\cdot7+37=100\)

a)  \(A=x^2+2xy+y^2-4x-4y+1\)

\(=\left(x+y\right)^2-4\left(x+y\right)+1\)

\(=3^2-4.3+1=-2\)

b)  \(B=x\left(x+2\right)+y\left(y-2\right)-2xy+37\)

\(=x^2+2x+y^2-2y-2xy+37\)

\(=\left(x-y\right)^2+2\left(x-y\right)+37\)

\(=7^2+2.7+37=100\)

c)  \(C=x^2+4y^2-2x+10+4xy-4y\)

\(=\left(x+2y\right)^2-2\left(x+2y\right)+10\)

\(=5^2-2.5+10=25\)

a) \(A=x^2+2xy+y^2-4x-4v+1\)

\(=\left(x+y\right)^2-4\left(x+y\right)+1\)

\(=3^2-4.3+1=-2\)