(1a) Do 4x and 15 + x have the same value when x is 5? How do you know?

Yes, both have the same value ( 20) when x = 5.

Step-by-step explanation:

We have two functions:

y = 15 + x

y = 4*x

We want to see if these functions have the same value when x = 5.

Then we just need to replace x by 5 in both equations, and see if the values of y are the same

first function:

y = 15 + 5 = 20

second function:

y = 4*5 = 20

So yes, both functions are equal to 20 when x = 5.

Yes.

Step-by-step explanation:

4(5)=20

15+5=20

in simplified version   it would be x ≤-4

step-by-step explanation:

multiply each term in x ≤-4 by -1