The answer is c to your question
Answer:
70 oz
Step-by-step explanation:
You know that one kitten weighs 2 lbs 4 oz. and the other ways 2 lbs 2 oz all you need to do is add that together to get 4 lbs 6 oz then convert that into lbs (1 lbs = 16 oz)
In total the 4 lbs gets you 64 oz, then you just need to add the 6 remaining oz to get 70 lbs!
If you have multiple equations with multiple variables, you can either do clever substitutions, or turn it into a matrix on which you can perform linear combinations or multiplications (Gauss elimination)
1 1 1 1
2 1 -1 8
1 -1 1 -5
(note how the above 3 rows represent the 3 equations, just got rid of the variables, plus sign and equals sign)
subtract row1 from row3, that eliminates x and z from row 3.
1 1 1 1
2 1 -1 8
0 -2 0 -6
divide row3 by -2, that will give y a factor of 1
1 1 1 1
2 1 -1 8
0 1 0 3
The last row now says y=3
