Answer:
Amy has 12 5¢ coins
Step-by-step explanation:
Let <em>x</em> represent 20¢ coins and <em>y</em> represent 5¢ coins.
Amy has four more 20¢ coins than 5¢ coins. Hence:

And the total value of all her coins is $3.80. Thus:

This yields a system of equations:

We can solve by substitution. Substitute the first equation into the first:

Distribute:

Combine like terms:

And divide both sides by 0.25. Hence:

Thus, Amy has 12 5¢ coins.
Using the first equation:

Substitute:

Thus, Amy has 16 20¢ coins.
In conclusion, Amy has 12 5¢ coins and 16 20¢ coins.
Answer:
(2,16)
Step-by-step explanation:
y=-x+18
y=8x
8x=-x+18
8x+x=9x
-x+x=0
9x=18
9x/9=x
18/9=2
x=2
y=8(2)
y=16
Surface area of a cube is given by
SA=6a²
but
SA=150 in²
thus
150=6a²
solving for a we obtain:
150/6=a²
a²=25
thus
a=√25
a=5 inches
hence the side length is 5inches
Answer:
0.222
Step-by-step explanation:
out of 36 outcomes you have 8 possible outcomes for a '4' or '6':
1,5
5,1
3,3
2,4
4,2
2,2
1,3
3,1
8/36 = 2/9 = .2 repeating