How do you determine which variable to substitute in for?

Substituting for a Variable

If you know the value that the variable is equal to, you can substitute that value in for the variable in the expression! Let's look at an example. Since we know that x=5, we can directly substitute or replace the x in the expression x+3 with a 5 to solve for y!

Step-by-step explanation:

I hope this kinda helps

d

step-by-step explanation:

option c) graph of line going through 1, 4 and 3, 10

step-by-step explanation:

let y equal to margo's coin collection

let x equal to number of years

at the begining x=0, y=1 → point=(x,y)→point=(0,1)

she adds 3 coins per year, then y=1+3x

at x=1, y=1+3(1)=1+3→y=4→point=(x,y)→point=(1,4)

at x=3, y=1+3(3)=1+9→y=10→point=(x,y)→point=(3,10)

the graph of line going through (1, 4) and (3, 10), then the option c is the correct.