Question

Can somebody help me to explain, in complete sentences, how you would I use the elimination method to solve the following system of equations. and also give me the solution? thank you

6x – 5y = 4
9x + 4y = –17

Answer 1

eliminate y from second equation

Answer 2

can you please explain that to me so I can write it? Thanks

Answer 3

this is what I wrote :"I can use the elimination method to solve system equations because if I know how to solve for one variable i can get rid of the other one. "
But I still dont know the asnwer to the problem..

Answer 4

first you would need to make one of the variables the same value

we will use the y variable for example only because it would be easier as one of them is already a negative and one is a positive

so to make them both the same value you must multiply the two equations by something

6x – 5y = 4 (multiply by 4)
9x + 4y = –17 (multiply by 5)

which will give you

24x - 20y = 16
45x + 20y = -85

add both the equations together
the y variables will cancel eachother out because they are now the same value and when you add them together they will cancel eachother out because one is a negative and one is a positvive
so you will now get

69x = -69

now to get the x variable on its own you must divide both sides by the number next to x

69x / 69 = -69 / 69

x = -1

now we know what x is we can use this to work out what the y variable is
so we go back to our original equations and choose either one
for this example i will choose the first equation

6x – 5y = 4

now everywhere you see the variable x you replace it with the value we have found which is -1
so the equation will now look like this

6(-1) -5y = 4

which is

-6 -5y = 4

rearrange this so we have the variable on one side and the numbers on the other
remember when bringin a variable or a number to the other side will change its value to the opposite e.g. bringin -6 to the other side will make it +6

so you now have

-5y = 4 + 6

-5y = 10

-5y / 5 = 10 / 5

-y = 2

now to change the y into positive we swap the sides around
turning the y into a positive and the number 2 into a negative

-2 = y

put the two figures we have found in the formula to check if you get the same answer.

remember to click good answer

Answer 5

thank you.. and I did