Algebra Homework Help

Ok so with this information i need to know the cost of 1 two by six and the cost of one two by fours.

30 Two by fours and 50 two by sixes had a cost of 341$.
70 two by fours and 10 two by sixes had a cost of 273$

If someone could tell me the cost of 1 two by four and 1 two by six with that info that would be great!

 

Sorry was late at night and I messed up haha

 

TO DISPROVE THE GUY ABOVE ME; 70 X 50 is NOT = to 250, it is 350.

Make one of the variables equal.
This is called the elimination method.
Lets call the 2x4's X, and the 2x6's Y's.

20x+50y=$341
70x+10y=$273

To get them equal, multiply the bottom equation by 5. This will make the Y's equal.

20x+50y=$341
5(70x+10y=$273) -> 350x+50y=$1365

Make this into an equation;

350x+50y=$1365
-20x+50y=$341

320x+0y=$1024
divide both sides by 320.

x=$3.20=Two by Fours

To fix 2x6's, plug 3.20 into one of the original equations;
20x+50y=$341
20(3.2)+50y=$341
64+50y=$341
50y=$277

Divide by 50
y=5.54

 

Just be careful about distributing the negative. It is important, especially in this case.

Should be:

350x+50y=$1365
-(20x+50y=$341)

So that +50y and -50y cancel out and you are only left with one variable.