500 people took part in a marathon. 35% of them were children and the rest were adults. How many adults took part in the marathon?

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

In the following diagram it is given that dec,ab || dc, ad || eb, and ad is congruent to bc. a)why isn't abc a parallelogram even though it has a pair of parallel sides and a pair of congruent sides b)explain why be must be congruent to bc. further explain what type of triangle this makes triangle abc and what it tells you about angle 1 and angle 2c) finally why must angle 3 be congruent to angle 1? further, explain why we know that angle 3 is congruent to angle 2

What is r i 4.5+10r=-6.5 with work pls