Question

Can someone explain the substitution method for literal equations?

Answer 1

do you have n example we can work thru?

Answer 2

Hold on

Answer 3

x - y = 4
4y - x = 14

Answer 4

to substitute means to replace with an equal value right?

Answer 5

x-y = 4 ; lets solve for x by +y to each side

x-y+y = 4+y
x+0 = 4+y

x = 4+y ; this is an equal value for x; we use it in the other equation now

Answer 6

The 3 rules I have are

1. Solve one of the equations for x or y
2. Substitute this expression into the other equation and solve for one unknown.
3. Place this value back into one of the equations and determine the other unknown.

Answer 7

4y - x = 14

4y -(4+y) = 14 ; distribute the - thru the (...)

4y -4 -y = 14 ; +4 to each side

4y -4+4 -y = 14+4

4y -y = 18 ; add your y's together

3y = 18 ; solve for y by /3 to each side

y = 6

Answer 8

since y = 6 is a solid value; we can use it in our equation to find x

recall that: x = 4+y ; and we now know that y = 6

x = 4+6 = 10

Answer 9

you can put it back into another equation if you want, but why bother with that since you already found an equation for x :)

Answer 10

Thanks again!

Answer 11

youre welcome...again :)