Help plessse I can’t get the answer

Prove that quadrilateral is a rhombus.

Brainliest ! which of the coordinates are not of th vertices of the feasible region for the system of inequalities y≤4,,x≤5,x+y> 6 a(2,4) b(0,6) c(5,4) d(5,1)

Find the least common denominator for thesetvo rational expressions.n^2/n^2+4n+4 -3/n^2+7n+10