Nothing further can be done with this solution
Answer:
About 3 years Speedy Jet printers be guaranteed.
Step-by-step explanation:
Given : Quality control studies for Speedy Jet Computer Printers show the lifetime of the printer follows a normal distribution with
mean
and standard deviation 
If the company wishes to replace no more than 10% of the printers.
To find : How long should Speedy Jet printers be guaranteed ?
Solution :
Using Z- table,
Z value corresponding to 10% or 0.10 = -1.28.
Applying z-score formula,

The value of x is given by,

Substitute the values,



So, approx 3 years.
Therefore, About 3 years Speedy Jet printers be guaranteed.
y=7x-5 This is the same as saying y-7x = -5 Well easy. You just make up numbers that make this work. Let x be 1 y-7=-5 y=-5+7 y=2 So one ordered pair is (1,2) Let x=2 y-14=-5 y=9 So another ordered pair is (2,9) Let x=3 y-21=-5 y=-5+21 y=16 So another ordered pair is (3,16)
hope it helps
Every time x is added by one, y is added by three.