What should be done to these equations in order to solve a system of equations by elimination?
-32 + 2y = 16
2x + 5y = 21
A:multiply the first equation by 3 and the second equation by 2

B:nothing needs to be done

C:multiply the first equation by 2 and the second by 3

D:multiply the first equation by 3

Use the following statements to write a compound statement for the conjunction or disjunction. then find its truth value. p: an isosceles triangle has two congruent sides. q: a right angle measures 90° r: four points are always coplanar. s: a decagon has 12 sides. a) a right angle measures 90° or an isosceles triangle has two congruent sides; true. b) a right angle measures 90° and an isosceles triangle has two congruent sides; true. c) a right angle measures 90° and an isosceles triangle does not have two congruent sides; false. d) a right angle measures 90° or an isosceles triangle does not have two congruent sides; true.