Answer:
1.) 10x-5=y
2.) $85
3.) 5.25 yards of fabric.
Explanation:
1.) To write an equation for this problem, we need to figure out what every value means:
the variable x, represents the amount of yards of fabric you can buy
the variable y, represents the total amount of money after you found out (x) or the amount of yards of fabric.
1 yard of fabric equals $10, and we have a $5 coupon (-5)
Our equation is:
10x-5=y
This equation represents the relationship between the total cost of fabric, and the amount that you can buy.
2. In order to solve this problem we need to use our equation, one value is given which is 9.
9 represents x, the amount of yards of fabric.
Substitute 9 into x:
10(9)-5=y
Solve:
90-5=y
85=y
85 represents the cost of 9 yards of fabric, including the $5 coupon.
3.) This problem is similar to #2, although it's flipped.
The value given is $47.50, which represents (y), the total amount of money after (x) was found out.
But, we need to figure out (x).
Substitute $47.50 into (y):
10(x)-5=$47.50
Next, we need to figure out x by solving the opposite.
Adding the coupon to our answer can represent 10(x).
$47.50+5=52.50
10(x)=52.50
Lastly, divide both sides of the equation by 10.
10(x) / 10=52.50 /10
x=5.25
5.25 represents the amount of yards of fabric purchased if you paid $47.50.