So,
To find the percentage that the copper comprises, just divide the amount of copper by the total amount of metal in the coin. In this case, we will change the denominator so that it is 100, which can easily be converted into a percentage, which is really just a fraction out of 100.

75%
75% of the metal in the coin is copper.
Answer:
1.
a = 112
b = 68
c = 68
2.
a = 127
3.
a=35
b=40
c=35
d=70
4.
a= 30
b=70
c = 30
d=70
e = 130
I'll help you with the rest later
Step-by-step explanation:
a = 112 because of allied angles rule
b and c = 68 because of angles at a point
360-112-112 ÷2
2. a = 127 because of angles on a straight line rule.
180-38-15
3. d= 70, vertically opposite angle
using angles on a straight line, 180 - 70 - 40 ÷ 2
we now have the two angles and because they are vertically opposite a and c = 35
b = 40 because of vertically opposite angles
4. a=30 because 90-70
since a=30, take 90 - 30 to get b, 70
d= 70, vertically opposite angles
e = 130 because a+b+c, vertically opposite angles
Answer:
y = -6
Step-by-step explanation:
Use the calculator to find:
169^2=169*169=28561
The whiteboards she bought cost $35, and she spent a total of $51.20, subtract to find out the total amount she spent on posters:

So she spent a total of $16.20 on posters, now divide by the amount one poster costs to find out how many posters she bought.

So she bought 3 posters.