The second matrix system is the correct answer
Answer:
5/12 = 0.416666667 if you round up to the nearest thousandths it would be 0.417
Here are a bunch of CORRECT answers. Your answer is in the first pic. I got number 3 wrong, but it still showed the correct answer.
21 blocks, because if he uses 38 you subtract 17 and you get 21
Step 1: 13+5x=30
step 2: subtract 13 from both sides; then youd get 5x=17
step 3: divide by 5
step 4: x=3.4
i hope this is what you were looking for