LetX1={5,10,15,20}andY1={5,10,15,20 ,25}. Using the formal definition of a func-tion, determine which of the following subsets ofX1×Y1correspond to the functions ofX1→Y1.
Justifyyour answer by providing reasons why each is or is not a function.
a) 1(a)f={(5,20),(10,15),(5,10),(15,5) ,(20,5)}
b) 1(b)f={(5,25),(10,5),(15,5),(20,10) ,(5,25)}
c) 1(c)f={(5,5),(10,5),(15,5)}

Galen sold tickets of his church’s carnival for a total of $2,820. children’s tickets cost $3 each and adult tickets cost $5 each. the number of children’s tickets sold was 30 more than 3 times the number of adult tickets slod. how many children’s ticket and how many adult tickets did he sell?

Nina has prepared the following two-column proof below. she is given that ∠oln ≅ ∠lno and she is trying to prove that ol ≅ on. triangle oln, where angle oln is congruent to angle lno step statement reason 1 ∠oln ≅ ∠lno given 2 draw oe as a perpendicular bisector to ln by construction 3 ∠leo ≅ ∠neo transitive property of equality 4 m∠leo = 90° definition of a perpendicular bisector 5 m∠neo = 90° definition of a perpendicular bisector 6 le ≅ en definition of a perpendicular bisector 7 δole ≅ δone side-angle-side (sas) postulate 8 ol ≅ on cpctc nina made two errors in the proof. identify and correct the errors.

Fawn bought a total of 70 cakes for a tea party. she spent $3,025. fawn bought vanilla cakes for $22 each and a fruit filled cake for $55 each. the system of equations below can be used to find the number of vanilla cakes, v, and the number of fruit filled cakes, f, fawn purchased. which system of equations has the same solution as the system below.