Let's define the following equations:
PART A
A.1 Defining variables
x: Any given number of days
T: Number of posts of Tommy after any given number of days
E: Number of posts of Elizabeth after any given number of days
P: Total numbers of posts
A.2 Writing an algebraic expression
By writing an algebraic expression to describe the combined number of posts for Tommy and Elizabeth after any given number of days we have:
For Tommy:
T = 11x
For Elizabeth :
T = 15x
So, the algebraic expression that combines the number of posts for Tommy and Elizabeth after any given number of days is:
P = 11x + 15x
∴ P =26x
PART B
B.1 Pictures of Tommy and Elizabeth after 7 days
This can be found using the expression:
P =26x
So, since x = 7, the total numbers of posts of Tommy and Elizabeth is:
P = 26(7)
∴ P = 182 posts on Instagram
B2. How do we know this?
It's simple, we have said that x represents any given number of days. So, the number of days is the same for everyone. Therefore, this can be demonstrated as follows:
For Tommy:
T = 11x
T = 11(7) = 77 posts
For Elizabeth:
E = 15x
E = 15(7) = 105 posts
Finally:
T + E = 77 + 105
T + E = 182 posts
