A. 38
Let X = seventh graders
6th graders are twice the number of 7th graders; therefore, 6th graders will be 2X.
The total number of students is 57.
2X + X = 57
3X = 57
X = 57 / 3
X = 19
IF X represents the 7th graders; there are 19 seventh graders present.
Since 6th graders are represented by 2X; Then, 2 * 19 = 38 is the number of 6th graders present.
Add both numbers to check: 19 + 38 = 57.
A energy can never be completely used up. When something "runs out of energy" it just runs out of use able energy that can be used to do the task that it was doing in the first place so it is now useless to that object and it must move on to be used for a different object.
Answer:
1) −5≠−4
False
2) 12≠15
False
Step-by-step explanation: I guess this is what you looking for, hope this help