equations with more than one letter?

Answer 1

if you have an 2 equations with more than one letter, first solve one equation for one of the letters, then substitute it into the other equation to find the answer

ex:
x + y = 17
3x + 2y = 39

take x + y = 17 and solve for x:
x = 17-y

now take 17-y and plug it in for x in the second equation:
3x + 2y = 39
3(17-y) + 2y = 39

distribute the 3
51-3y + 2y = 39

combine like terms:
51-y = 39

subtract 51 from both sides
-y = -12

Divide both sides by -1
y=12

Now take 12 and plug it in for y in the first equation:
x + y = 17
x + 12 = 17
x = 5

That is how you solve for 2 variables using substitution. You can do the same thing with 3 variables as well, its just a little more complicated and requires more information on the problem.

Answer 2

u mean how to solve for more than one unknown?
u need to make more equations and sub into one another....
EX:
x-y=5
x^2 + y = x-2


to solve that u need to decide which UNKNOWN u want find first.
I'm gonna solve for x first:
equation 1:
x-y=5
y=x-5
equation 2:
x^2 +y = x-2
SUB equation 1 into equation 2
x^2 + (x-5) = x-2
x^2 + x - 5 = x - 2
x^2 = 3
x= SQRT(3)
x=1.732
TO SOLVE FOR Y PLUG SOLUTION X INTO EQUATION 1
y=x-5
y=(1.732)-5
y=-3.2679

Answer 3

Solve for one letter, then substitute into your answer

Answer 4

what is the question exactly?