First we need to make both fractions equal to each other, and that means having to have the denominators the same.
What both 3 and 12 easily go into is 12.
So we need to make both fractions have a denominator of 12, so we multiply.
2/3 * 4/4 = 8 / 12
1/4 * 3/3 = 3 / 12
Now, we know that she has 8 / 12 pounds, and she uses 3 / 12 of it, so now we subtract to find how much she has left.
8 - 3 = 5
Out of the 12 pounds of roast beef, she now has 5 / 12 left.
Remember, you can do ANYTHING to an equaiton as long as you do it to BOTH SIDES
we can try to get k by itself bymaking that -17 into 0 since k+0=k
-17+17=0 right so
K-17=-12
add 17 to BOTH SIDES
K+17-17=17-12
K+0=5
K=5
