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You solve simultaneous equations involving negatives the same way you solve simultaneous equations not involving negatives. You subtract an appropriately scaled version of one from the other in order to cancel the terms of one variable, solving for the other variable. Remember that multiplying by -1 will reverse the signs, so that can be a trick to being able to visualize the subtraction. An example...
3x - 2y = 7
4x + 4y = -3
Multiply the first equation by -2 and solve for x...
-6x + 4y = -14
4x + 4y = -3
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-10x = -11
x = 1.1
Backsubstitute and solve for y
3x - 2y = 7
3.3 - 2y = 7
-2y = 3.7
y = -1.85
Its just a matter of keeping the signs straight and remembering that subtracting a minus means to add. You can also add the equations instead of subtracting, if it seems that would also cancel a term.
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What are simultaneous equation in maths?
Simultaneous equations are where you have multiple equations, often coupled with multiple variables. An example would be x+y=2, x-y=2. To solve for x and y, both equations would have to be used simultaneously.
9x-5y-4 equals 0 Solve for y?
Can't be done unless you have another equation with the same x and y. Then you would solve for simultaneous equations.
How do you solve the problems with two variables?
The analytical method involves simultaneous equations but if you do not know that, draw graphs of the equations: with one variable represented per axis. The solution, if any, is where the graphs meet.
How do you work a simultaneous equation?
You cannot work a simultaneous equation. You require a system of equations. How you solve them depends on their nature: two or more linear equations are relatively easy to solve by eliminating variables - one at a time and then substituting these values in the earlier equations. For systems of equations containing non-linear equations it is simpler to substitute for variable expression for one of the variables at the start and working towards the other variable(s).
How do you solve x minus y equals 6 and x plus y equals -2?
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