#1.
-x + 10y = 60
-4x + 16y = 32
If we need to use the substitution method, we choose an equation and let one of the variable in terms of the other. Then we substitute it to the other equation.
Here, let's choose the first equation.
-x + 10y = 60
Then let's choose the variable x. If we choose x, we must represent it in terms of the other variable (which is y):
-x + 10y = 60
-x = -10y + 60
x = 10y - 60
Finally, substitute it to the second equation:
-4x + 16y = 32
-4(10y - 60) + 16y = 32
Solving for y,
-40y + 240 + 16y = 32
-24y = 32 - 240
-24y = -208
y = 26/3
Substituting to the expression for x:
x = 10(26/3) - 60
x = 260/3 - 180/3
x = 80/3
Now, try doing #2.
Hope this helps :)
1) -x+10y=60
-4x+16y=32
2) -1/2x - 1/4y=3
1/3x+1/6y=2
4 answers
Jai - thanks. I tried #1 before you answered and I hot x=32 and y = 6. Wrong??? It worked out in the check
Also, tried #2, getting real lost with the fractions:( Please Help!
Also, tried #2, getting real lost with the fractions:( Please Help!
It's wrong, I don't know how you checked but x = 32 and y = 6 actually doesn't satisfy either given equation.
Anyway, okay let's do #2.
-1/2x - 1/4y = 3
1/3x + 1/6y = 2
To deal with fractions, it's easier if you first make them whole numbers by multiplying by their LCD (least common denominator).
We multiply the first equation by 4, and we'll get:
-2x - y = 12
We multiply the first equation by 6, and we'll get:
2x + y = 12
Now, if we try adding them,
-2x - y = 12
2x + y = 12
----------------------
0 + 0 = 24
0 = 24
which is absolutely impossible. Therefore, no solutions exist. (If you plot them, they are actually parallel to each other, and indeed, no solutions exist as they will never intersect)
Hope this helps :3
Anyway, okay let's do #2.
-1/2x - 1/4y = 3
1/3x + 1/6y = 2
To deal with fractions, it's easier if you first make them whole numbers by multiplying by their LCD (least common denominator).
We multiply the first equation by 4, and we'll get:
-2x - y = 12
We multiply the first equation by 6, and we'll get:
2x + y = 12
Now, if we try adding them,
-2x - y = 12
2x + y = 12
----------------------
0 + 0 = 24
0 = 24
which is absolutely impossible. Therefore, no solutions exist. (If you plot them, they are actually parallel to each other, and indeed, no solutions exist as they will never intersect)
Hope this helps :3
Jai - it was -5x+10y=60. Typo - wow so sorry - but now was my answer right?