Horatio has 57 coins consisting of nickels, dimes, and quarters. he has twice as many dimes as
nickels. if the coins are worth a total of $7.25, which system of equations is used to determine
how many of each coin horatio has?
in + d + 9 = 57
n = 20
5n + 10d + 259 = 7.25
n + d + 9 = 57
n = 2d
0.05n + 0.100 + 0.259 = 7.25
nt d + 9 = 57
d = 2n
5n + 10d + 259 = 7.25
nd + 9 = 57
d = 2n
0.05n + 0.10d + 0.259 = 7.25

Which of the following multiplication expressions can be modeled by the tiles shown? check all that apply. 8(3) = 24 6(4) = 24 (3)(12) = 36 24(3) = 72 3(8) = 24 2(12) = 24

Exercise: counting committees 0.0/2.0 puntos (calificable) we start with a pool of n people. a chaired committee consists of k≥1 members, out of whom one member is designated as the chairperson. the expression k(nk) can be interpreted as the number of possible chaired committees with k members. this is because we have (nk) choices for the k members, and once the members are chosen, there are then k choices for the chairperson. thus, c=∑k=1nk(nk) is the total number of possible chaired committees of any size. find the value of c (as a function of n ) by thinking about a different way of forming a chaired committee: first choose the chairperson, then choose the other members of the committee. the answer is of the form c=(α+nβ)2γn+δ. what are the values of α , β , γ , and δ ?

Solving systems by substitution answer fast