Teacher's Guide - Pearson

Activity 15.5 (Student’s Book page 279)6. a) (x 1 1) 2b) (x 1 2) 2c) (x 1 6) 2d) (2x 2 1) 2Exercise 15.7 (Student’s Book page 280)1. a) (a 1 2) 2b) (y 1 7) 2c) (x 1 y) 2d) (b 2 8) 2e) (2x 1 y) 22. a) (k 2 9)b) (7a 2 5b)c) (3a 1 2b)Investigation (Student’s Book page 281)1. a) AB 5 3, BC 5 4, AC 5 5b) AB 5 8, BC 5 6, AC 5 10c) AB 5 5, BC 5 12, AC 5 132. Yes. The sides satisfy the equation a 2 1 b 2 5 c 2 .3. For right-angled triangle ABC:AC 2 5 AB 2 1 BC 2= (m 2 2 n 2 ) 2 1 (2mn) 2= m 4 2 2m 2 n 2 1 n 4 1 4m 2 n 2= m 4 2 2m 2 n 2 1 4m 2 n 2 1 n 4= m 4 1 2m 2 n 2 1 n 4= (m 2 1 n 2 ) 2= AC 2Extension Activity 15.3 (Student’s Book page 281)Hypotenuse 5 ​√ ________________(n 2 2 4) 2 1 (4n) 2 ​5 ​√ ____________________n 2 2 8n 1 16 1 16n 2 ​5 ​√ _______________17n 2 1 8n 1 16 ​Chapter 15: Working with variables93