Makahanap ng mabilis at maaasahang mga solusyon sa iyong mga problema sa IDNStudy.com. Magtanong at makakuha ng detalyadong sagot mula sa aming komunidad ng mga eksperto na may kaalaman.

Prove that: [(x+y)+(x-y)][(x+y)-(x-y)]= 4xy

Answer please


Sagot :

*using binomial theorem: [(x + y)^2 - (x - y)^2] = 4xy; [(x^2 + 2xy +y^2) - (x^2 - 2xy +y^2)] = 4; *eliminating x^2 and y^2: [2xy - (-2xy)] = 4xy; 4xy = 4xy
[(x+y)+(x-y)][(x+y)-(x-y)] = 4xy
[x+y+x-y][x+y-x+y]       === negative times positive x equals negative x and negative y times negative equals positive y , don't mind the 4xy on the opposite side!
[x+x+y-y][x-x+y+y] =4xy
[2 x][2 y] = 4xy
2x · 2y = 4xy
2 · xy = 4xy
4xy = 4xy
  √   =  √ They are equal, so this equation and the answer is equal to 4xy.