Linear regression

Complete this assignment on paper, and submit it physically to the teacher.
RECORD the time taken to complete the assignment on the top of the paper.

1. Simplify each expression where possible.
   a) 𝑥 + 𝑥 [1]
   b) 𝑥 + 𝑦 [1]
   c) 5𝑥 − 5 + 7𝑥 − 7 [2]
   d) 4𝑥 + 10𝑦 + 𝑥 − 𝑦 [2]
   e) 7𝑎
   2 + 8𝑎 − 4𝑎
   2 + 5𝑎 [2]
2. Given that 𝑎 = 5, 𝑏 = 6 and 𝑐 = −4, find the value of each expression.
   a) 3𝑎𝑐 [1]
   b) 𝑐
   2
   [1]
   c) 𝑎
   2 − 𝑐 [2]
   d) 3𝑎−44
   𝑐−𝑎
   [3]
3. A scuba diver is 15 m below sea level.
   A shipwreck is located 5 m directly below the diver.
   And a helicopter is located 20 m directly above the diver.
   a) Write an integer to represent the location of the diver. [1]
   b) Write an integer to represent the location of the shipwreck. [1]
   c) Write an integer to represent the location of the helicopter. [1]
   d) Use integers to find the distance between the helicopter and the diver.