Answer:
I have ordered <u>30</u> softballs of 11-inch and <u>50</u> soft balls of 12-inch.
Step-by-step explanation:
Let the number of 11-inch softball be 'x'.
Let the number of 12-inch softball be 'y'.
Given:
Total number of soft balls = 80
Now we know that.
Total number of soft balls is equal to sum of the number of 11-inch softball and the number of 12-inch softball.
framing in equation form we get;
![x+y=80 \ \ \ \ equation \ 1](https://tex.z-dn.net/?f=x%2By%3D80%20%5C%20%5C%20%5C%20%5C%20equation%20%5C%201)
Also Given:
Price of 11- inch softball = $2.75
Price of 12-inch softball = $3.25
Total Bill = $245
Now we know that;
Total bill of soft balls is equal to sum of Price of 11- inch softball multiplied by the number of 11-inch softball and Price of 12- inch softball the number of 12-inch softball.
framing in equation form we get;
![2.75x+3.25y = 245 \ \ \ \ equation \ 2](https://tex.z-dn.net/?f=2.75x%2B3.25y%20%3D%20245%20%5C%20%5C%20%5C%20%5C%20equation%20%5C%202)
Now Multiplying equation 1 by 3.25 we get;
![3.25(x+y)=80\times 3.25\\\\3.25x-3.25y = 260 \ \ \ \ equation \ 3](https://tex.z-dn.net/?f=3.25%28x%2By%29%3D80%5Ctimes%203.25%5C%5C%5C%5C3.25x-3.25y%20%3D%20260%20%5C%20%5C%20%5C%20%5C%20equation%20%5C%203)
Now Subtracting equation 2 from equation 3 we get;
![(3.25x+3.25y)-(2.75x+3.25y)=260-245\\\\3.25x+3.25y-2.75x-3.25y = 15\\\\0.5x = 15](https://tex.z-dn.net/?f=%283.25x%2B3.25y%29-%282.75x%2B3.25y%29%3D260-245%5C%5C%5C%5C3.25x%2B3.25y-2.75x-3.25y%20%3D%2015%5C%5C%5C%5C0.5x%20%3D%2015)
Dividing both side by 0.5 we get;
![\frac{0.5x}{0.5}= \frac{15}{0.5}\\\\x= 30](https://tex.z-dn.net/?f=%5Cfrac%7B0.5x%7D%7B0.5%7D%3D%20%5Cfrac%7B15%7D%7B0.5%7D%5C%5C%5C%5Cx%3D%2030)
Now Substituting the value of 'x' in equation 1 we get;
![x+y=80\\\\30+y=80\\\\y =80-30 =50](https://tex.z-dn.net/?f=x%2By%3D80%5C%5C%5C%5C30%2By%3D80%5C%5C%5C%5Cy%20%3D80-30%20%3D50)
Hence I have ordered <u>30</u> softballs of 11-inch and <u>50</u> soft balls of 12-inch.