McFart: Why is algebra not straight across the board in ways to solve?
Collage algebra: I have the textbook explain all the infamous details on how to solve equations then when it comes test time the problems are not of the same in which it was explained with. Why is this?
Answers and Views:
Answer by FreddyM
You have to figure out what the question is asking you and how to replicate the questions in the textbooks. The exam questions usually follow a similar pattern.
When it comes to Algebra, just remember a few simple rules
1) Group similar variables together (x with x, y with y. Example: 5x=2x+3. Subtract 2x from both side, you get 5x-2x=3)
2) Only 1 of each variable should appear in the formula (5x-2x = 3x. Therefore 3x=3.)
3) Make it so all numbers in front of the variable (x, y, z, whatever) disappears. (Example, 3x=3, divided by 3. x = 1)
4) If there are more than one variables, get rid of all the other variables, and solve for just 1
Sometimes you need to move a number from one side of the equation to the other side. Just follow these simple rules:
1. Solve from the outside in. (i.e. 15x = 3(2x+3). Get rid of the 3 first by dividing both sides by 3. So you get 5x=2x+3
2. Get rid of all brackets, denominators, etc.
3. Move the variables to the left and the numbers to the right
4. If you have more than 1 equations, merge the equations until you only have 1
If you follow these rules, you can solve for the most complicated algebra problems
Example:
1) 3x+2y-2z=-2
2) 2x+y-z=-2
3) x-3y-z=0
Objective: Solve for X.
Method: Multiply first and second equation by 2, Merge 2 equations.
3x+2y-2z+2=4x+2y-2z+4
-x=2
x=-2
Objective: Solve for Y
Method: Merge second and third equations, substitute -2 for x
2x+y-z+2=x-3y-z
x+4y=-2
when x = -2
y = 0
Objective: Solve for Z
Method: substitute -2 for x, 0 for y. Use any equation. I’ll use the 1st equation
3x+2y-2z=-2
when x = -2, y = 0
-6-2z = -2
-2z = 4
z= -2
Therefore, x = -2, y = 0, z = -2
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