Which of the following is not a property of all rectangles? (1) both pairs of opposite side have equal lengths
(2) all angles are congruent
(3) the diagonals are congruent
(4) the diagonals are perpendicular​

Seymour is twice as old as cassandra. if 16 is added to cassandra’s age and 16 is subtracted from seymour’s age, their ages become equal. what are their present ages? show !

Answer asap ill give ! ’ a sample of radioactive material decays over time. the number of grams, y , of the material remaining x days after the sample is discovered is given by the equation y = 10(0.5)^x. what does the number 10 represents in the equation? a. the half-life of the radioactive material, in days b. the amount of the sample, in grams, that decays each day c. the time, in days, it will take for the samples to decay completely d. the size of the sample, in grams, at the time the material was discovered

Write the summation to estimate the area under the curve y = 1 + x2 from x = -1 to x = 2 using 3 rectangles and right endpoints