i mean:
3x-y=9 2x+y=6
x-2y=0 3x+y=0
-3x-y=9 2x+y=6
-x-2y=0 3x+y=0
tell me how to do one and i will try to do the other one..(use the substitutional method)
2 answers
3x-y=9 2x+y=6
I assume that is one question.
The easiest thing to get by itself is "y" in the 2nd part. If I have 2 xylophones and one Yankee, the way to get the Yankee by himself is to simply take away the 2 xylophones.
2x+y=6
y=6-2x
Now we know what the "yankee" is. He is 6 minus 2 xylophones.
Let's look at the other equation.
3x-y=9
3 xylophones minus the yankee equals nine.
So 3 xylophones minus (6 minus 2 xylophones) equals 9.
3x- (6-2x) = 9
3x - 6 + 2x = 9
Let's add the xylophones together.
5x - 6 = 9
Put the 5 xylophones by themselves. Easiest way is to add the -6 and 6.
5x = 15
If 5 xylophones are worth 15 dollars, how much is one worth?
15 divided by 5 is 3.
A xylophone is worth $3.
How much is the Yankee worth?
3x-y=9
We have 3 xylophones and they are worth $3. 3x3 = 9.
$9 minus the price of the yankee is ... Well ... $9 according to this.
9-y = 9
The yankee must obviously be worth nothing.
Y=0
X=3
i
I assume that is one question.
The easiest thing to get by itself is "y" in the 2nd part. If I have 2 xylophones and one Yankee, the way to get the Yankee by himself is to simply take away the 2 xylophones.
2x+y=6
y=6-2x
Now we know what the "yankee" is. He is 6 minus 2 xylophones.
Let's look at the other equation.
3x-y=9
3 xylophones minus the yankee equals nine.
So 3 xylophones minus (6 minus 2 xylophones) equals 9.
3x- (6-2x) = 9
3x - 6 + 2x = 9
Let's add the xylophones together.
5x - 6 = 9
Put the 5 xylophones by themselves. Easiest way is to add the -6 and 6.
5x = 15
If 5 xylophones are worth 15 dollars, how much is one worth?
15 divided by 5 is 3.
A xylophone is worth $3.
How much is the Yankee worth?
3x-y=9
We have 3 xylophones and they are worth $3. 3x3 = 9.
$9 minus the price of the yankee is ... Well ... $9 according to this.
9-y = 9
The yankee must obviously be worth nothing.
Y=0
X=3
i