Answer:
Increase by 8.75
Step-by-step explanation:
75+82+67+72=296
296/4= 74
74 = Original Mean
75+82+96+78=331
New mean 82.75
82.75-74=8.75
16 + 20 or 2 x 18
The x-value is -2
U can substitute any of the equations for y
-5x + (-9) = 2x + 5
-9 = 7x + 5
-14 = 7x
-2 = x
x = 2