For this case, the first thing we must do is define variables.
We have then:
x: number of years
y: total salary
For company 1 we have:
[tex] y = 2500x + 75000
[/tex]
For company 2 we have:
[tex] y = 5000x + 55000
[/tex]
By the time both salaries are equal we have:
[tex] 2500x + 75000 = 5000x + 55000
[/tex]
From here, we clear the value of x.
We have then:
[tex] 5000x - 2500x = 75000 - 55000
2500x = 20000
[/tex]
[tex] x = \frac{20000}{2500}
x = 8
[/tex]
Answer:
Brenda's salary would be the same with both companies in 8 years.