What is the property of 234+(-234)=0

Simplify the expression. enter the correct answer.

Use the diagonals to determine whether a parallelogram with vertices u(2,−2), v(9,−2), w(9,−6), and x(2,−6) is a rectangle, rhombus, or square. give all the names that apply.

Type the correct answer in each box. use numerals instead of words. if necessary, use / for the fraction bar. consider the given table.