You have 20 coins valued at 2.60. All are either quarters or nickels. Write and solve a system of equations to find the number of each coin you have.

To solve this problem you must apply the following proccedure:

1. You have a total of 21 coins, all nickels and dimes. Then:

x:nickels=5 cents

y: dimes=10 cents

x+y=21

2. You have that the total value is $1.70. Then:

5x+10y=170

3. The system of equation is:

x+y=21    (i)

5x+10y=170    (ii)

4. You have:

x+y=21

x=21-y

5(21-y)+10y=170

105-5y+10y=170

y=13 dimes

x+13=21

x=8 nickels

option a, c,d are correct.

step-by-step explanation:

from the given figure, it is given that z is equidistant from the sides of the triangle rst, then from triangle tzb and triangle szb, we have

tz=sz(given)

bz=zb(common)

therefore, by rhs rule,δtzb ≅δszb

by cpctc, sz≅tz

also, from δctz and δasz,

tz=sz(given)

∠tcz=∠saz(90°)

by rhs rule, δctz ≅ δasz, therefore by cpctc, ∠ctz≅∠asz

also,from δasz and δzsb,

zs=sz(common)

∠zbs=∠saz=90°

by rhs rule, δasz ≅δzsb, therefore, by cpctc, ∠asz≅∠zsb

hence, option a, c,d are correct.

(2,20) means that the 2 is 2 hours and 20 is 20$. so there both 20$ for 2 hours only the same price. like it says. so, the dunk tank and the bounce house are the same price (20$) for the same amount of time (2 hours).

hope i