C. add 3 to 15 because the sequence is +3 every time
Answer: d
explanation: baseball cards already take up half so it cant be a or c because those are more than half and if you add all of the numbers up you would get 40. 15 out if 40 is 3/8 and baseball cards take up 4/8 and football cards take up 1/8 so your answer would be d.
Answer:
See below (I hope this helps!)
Step-by-step explanation:
We need to write this in the form y = mx + b.
x + 3y = -12
3y = -x - 12
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
