How would I get the ordered pair for this algebra problem using the elimination method?

Equation 1
0.05x+0.25y=11
0.05x=11-0.25y
x=11-0.25y/0.05

Now substitute

Equation 2
0.15(11-0.25y/0.05)+0.05y=12

Then solve for "y"
Then solve for "x"

Multiplication and then subtraction, in that order.   You need to set x's or y's equal to one another by multiplying both sides by some constant.

I'll give you one way's steps for solving.

So, first ask yourself what you multiply .05 by to get .15?
Multiply by that constant on the left and right side of the equals signs for 0.05x + 0.25y = 11.

It should look like this:

c*0.05x + c*0.25y = 11*c, where c is a constant such that c * 0.05 = 0.15

Then, put one equation above the other and subtract.

  0.15x + whatever = whatever
- (0.15x + 0.05y) = 12
___________________
Use algebra to solve for Y.


Then, you can plug whatever Y equals into either of the original equations.

P.S. - Lolli is using the substitution method, not the elimination method.  So, don't follow her method or you might get marked down by your teacher.  Even though it would be cool if you learned how to use substitution, also.

0.05x + 0.25y = 11
0.15x + 0.05y = 12

To use the elimination method, you need the same or opposite amounts of one of the variables.

Multiply the first equation by 3 to have the same x value in both equations, or multiply the second equation by 5 to have the same y value in both equations.

Multiply first equation by 5.

0.15x + 0.75y = 33

0.15x + 0.05y = 12

Subtract the second equation from the first.

0.15x - 0.15x + 0.75y - 0.05y = 33 - 12

0.70y = 21 Look ma, no x term!

y = 30

Go back and solve for x.

0.05x + 0.25y = 11

0.05x + 0.25(30) = 11

0.05x + 7.5 = 11

0.05x = 3.5

x = 70

(70, 30)