Answer:
Nick sank 8 shots
Step-by-step explanation:
* <em>Lets explain how to solve the problem</em>
- Assume that Nick sinks x shots and misses y shots
- Nick attempts a total of 28 shots
- That means he sinks and misses 28 shots
∴ x + y = 28 ⇒ (1)
- His father give him 5 points (+5) for every sank shot and takes away
2 points (-2) for every missed shot
- That means his score calculated by adding (<u><em>the number of sank shots</em></u>
<em> </em><u><em>multiplied by 5</em></u>) and (<u><em>the number of missed shots multiplied by (-2)</em></u>)
- Nick ends up with zero points
∴ 5x + (-2)y = 0
- Remember: (+)(-) = (-)
∴ 5x - 2y = 0 ⇒ (2)
* <em>Now we can solve the two equations by elimination method to find</em>
<em> the number of sank shots</em>
- Multiply equation (1) by 2 to eliminate y
∴ 2x + 2y = 56 ⇒ (3)
- Add equations (2) and (3)
∴ 7x = 56
- Divide both sides by 7
∴ x = 8
∵ x represents the number of sank shots
∴ Nick sank 8 shots