Step-by-step explanation:
hope it will help you......
Answer:
p = 17
→ Expand out (21)² - (17)²
21² = 441 and 17² = 289 therefore 441 - 289 = 152
→ Plug value back into equation
441 - p² = 152
→ Minus 441 from both sides
- p² = -289
→ Square root both sides
