The mistake is in step 3:
I: −2m =−12 − 2n
II: 2m = 8 + 8n
the student set both right sides of the equations equal (−12 − 2n = 8 + 8n), but the left sides aren't equal: first equation has -2m, second has +2m so the signs of one of the equations must be inverted first
Answer:
B
Step-by-step explanation:
The answer is B I have seen this question befor
Answer:
30 are present 10 are absent
Step-by-step explanation:
75%=3/4
so 3/4 of them are absent
3/4(40)=30
and 40-30=10 are absent
Answer:
Step-by-step explanation: