Question

(x+y)the whole square -4xy
please expalin using identities

Answer 1

${(x - y)}^{2} = {x}^{2} + {y}^{2} - 2xy$
and your question is
${(x + y)}^{2} - 4xy$
so
${x}^{2} + {y}^{2} + 2xy - 4xy$
${x }^{2} + {y}^{2} - 2xy$
get formula
${(x - y)}^{2}$