Question

Please help me solve this! Algebra II

Answer 1

Thing is, I don't know how to solve it

Answer 2

solve for 1 variable and then substitute. then solve for the other then substitute again. Or you can just add and eliminate one of the variable. It is going to help if you add because if you do add, you will cancel the "x"

Answer 3

and yea, this can be part of a calculus problem but i am assuming it purely algebra.

Answer 4

I learned about it too, I just don't understand it at all! You have to take two equations and take away one and then solve something and then add into the other equation. It's confusing!

Answer 5

i sit calculus or algebra?

Answer 6

algebra II

Answer 7

So could anyone help me solve this or

Answer 8

Using substitution.

Rearrange equation 2
x=33+3y-4z

Substitute equation 2 into the first equation

3(33+3y-4z)-2y+2z=30
99+9y-12z-2y+2z=30

Combine like terms and simplify
7y-10z=-69

Substitute equation 2 into the third equation
2(33+3y-4z)-4y+3z=42
66+6y-8z-4y+3z=42

Combine like terms and simplify
2y-5z=-24

We now have eliminated the variable x and have two equations with two unknowns
7y-10z=-69
2y-5z=-24

Answer 9

Now solve for y and z using the two equations

7y-10z=-69
2y-5z=-24

Rearrange the second equation

y=-12+5/2z

Substitute into the first equation
7(-12+5/2z)-10z=-69
-84+35/2z-10z=-69

Combine like terms and simplify
15/2z=15

Solve for z
z=2

Substitute z into the second equation and solve for y
2y-5(2)=-24
2y-10=-24
2y=-14
y=-7

Solve for x by substituting -7 for y and 2 for z in the one of the original three equations

Using equation 2 solve for x

-x+3(-7)-4(2)=-33
-x-21-8=-33
-x=-4
x=4

Answer 10

Check the answer using the two other original equations
3(4)-2(-7)+2(2)=30
12+14+4=30
30=30

2(4)-4(-7)+3(2)=42
8+28+6=42
42=42

Answers check

Answer 11

I suggest you go watch a few youtube videos on simultaneous equations with three variables.

http://www.youtube.com/watch?v=HEXbmERkDzc