# Algerbra

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Q1. Solve the system of equationd by addition method.
-2x+y=6
-3x-4y=20

Select the correct choice below and, if necessary, fill in the answer box to comlete your choice
b) Infinitely many solutions
c) No Solution

Q2. Solve the system of equationd by addition method.
6x+4y=-10
2x-4y=-30

Select the correct choice below and, if necessary, fill in the answer box to comlete your choice
b) Infinitely many solutions
c) No Solution

Q3. Solve the system of equationd by addition method.
2x+4y=7
4x+8y=0

Select the correct choice below and, if necessary, fill in the answer box to comlete your choice
b) Infinitely many solutions
c) No Solution

Q4. Solve the system of equationd by addition method.

-2x=-2y-8
-4x+2y=-16

Select the correct choice below and, if necessary, fill in the answer box to comlete your choice
b) Infinitely many solutions
c) No Solution

Q5. Solve the system of equationd by addition method.

-3x-5y=7
5x+15y=7

The solution is ___

Q6. Solve the system of equationd by addition method.

(x/2)-(y/6)=-1
(x/4)+(y/12)=-3

Select the correct choice below and, if necessary, fill in the answer box to comlete your choice
b) Infinitely many solutions
c) No Solution

Q7. Solve the system of equationd by addition method.

(x/7)-y=2
-(x/2)+(7y/2)=-7

Select the correct choice below and, if necessary, fill in the answer box to comlete your choice
b) Infinitely many solutions
c) No Solution

Q8.Solve the system of equationd by addition method or the substitution method

x+(1/20y)=(1/4)
3x+2y=2

The solution is ______

• Algerbra - ,

We do not do your homework for you. Although it might take more effort to do the work on your own, you will profit more from your effort. We will be happy to evaluate your work though.

• Algerbra - ,

Well, actually, we do often do the homework. However, it's a bit daunting to get a whole problem set dumped out, especially when all the problems are similar. I'll do Q6 to get you started. It is complicated enough that its solution should help you with the others.

(x/2)-(y/6)=-1
(x/4)+(y/12)=-3

Some people revel in working with fractions, but I find them a burden. So, get rid of all those nasty denominators. Multiply the first equation by 6, and the second by 12:

3x - y = -6
3x + y = -36

Now, add these equations and something magic happens -- the y's go away:

6x = -42
x = -7

Now, using either of the two equations, we can find y:

3x - y = -6
3(-7) - y = -6
-21 - y = -6
-y = 15
y = -15

Now, check to make sure your answer fits both of the original equations:

(x/2)-(y/6)=-1
-7/2 - (-15/6) = -1
-7/2 + 5/2 = -1
-2/2 = -1
-1 = -1

(x/4)+(y/12)=-3
-7/4 + (-15/12) = -3
-7/4 - 5/4 = -3
-12/4 = -3
-3 = -3