Question

Tommy posts 11 pictures on Instagram every day . Elizabeth posts 15 pictures on Instagram every day .

Answer 1

You can just think of any variable for example let's use "T" , "E". Then do T +E for part a. Then do T=11 E=15. After do 11 •7 and 15•7. 11•7=77 . 15•7=105. Last do 105+77 and it equals 182.

Answer 2

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