Answer:C- Her net income is less than $120.
Step-by-step explanation:
Multiply the dimensions to get 174,720 in^3
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
Answer: 440 dollars
Step-by-step explanation:
So -5x=-50
multiply both sides by -1
5x=50
divide by 5
x=10
check
-5 times 10=-50
-50=-50
check
