We have the following equation:
x2 + 4x = - (y2 - 20)
Let's review step by step:
step 1:
x2 + 4x = -y2 + 20
Answer: OK
step 2:
x2 + 4x + 4 = -y2 + 20 - 4
Answer: Wrong
The correct step is:
x2 + 4x - 4 = -y2 + 20 - 4
Or equivalently:
x2 + 4x + 4 = -y2 + 20 + 4
Answer:
he did make an error in his work in step 2
The average driving speed would be 62 because you add 198, 150, and 210 and divide the total by 9.
Hope this helped :)
Since 3/5 of an hour is 36 minutes and the robot can complete 8 tasks in 36 minutes. The remaining minutes are 24 and in 24 minutes the robot can do about 5 tasks so add 5 and 8 to get about 13 tasks in an hour.
Explanation: Just divide 36 by 24 to get 1.5 and divide 8 by 1.5 to get about 5. Then add 8 + 5 to get 13 the final result. So it’s 13 tasks. Sorry if I got it wrong.
a
0
=
4
a
i
=
a
i
−
1
+
7
XXXX
possibly with the restriction 1<=i<=4 if this is not intended to be a continuous sequence
Explanation:
This is a simple arithmetic sequence with a difference of
7
between ascending sequence terms.
