poor ixl 78+78 i think because it had 78 and she drove 78
Answer:
9x 2 equals 18. 72 divided by 18 is 4. So the answer is 4.
Step-by-step explanation:
The expression which relates the total time taken and the time taken for the trip is [15s + 15(s+2)] / s² + 2s and 2.32 hours respectively.
<em>Travel time = distance ÷ speed </em>
<u>Second half of the trip</u> :
- <em>Distance covered = 15 miles</em>
<u>Time taken for second half of trip</u> :
Time taken = 15 / s
<u>First half of the trip</u> :
- <em>Speed = s + 2 mph </em>
<u>Time taken for first half of trip :</u>
Time taken = 15 / (s+2)
<u>Total time taken :</u>
<em>First half + second half</em>
15/(s+2) + 15/s = [15s + 15(s+2)] / s² + 2s
B)
If s = 12
<em>Substitute s = 12 into the expression</em> :
[15(12) + 15(12+2)] / 12² + 2(12)
[180 + 210] / 144 + 24
390 / 168
= 2.32 hours
Therefore, the total time taken is 2.32 hours.
Learn more : brainly.com/question/18796573
Answer:
DE = 13.4 cm (to 1 decimal place)
Step-by-step explanation:
Given: ABCD is a square
BC = AC = 12 cm (opposite sides of a square are congruent)
E is midpoint of BC (given)
BE = EC = 12/2 = 6 cm
CD = AB = 12 cm (opposite sides of a square are congruent)
angle ECD is a right angle (interior angles of a square are 90 deg.)
Consider right triangle ECD
DE = sqrt(EC^2+CD^2) ............. pythagorean theorem
= sqrt(6^2+12^2)
= sqrt ( 36+144 )
= sqrt (180)
= 2 sqrt(45)
= 13.416 (to three dec. places)
The solution(s) of a system of linear equations give points of intersection of specific lines or planes.
The solution(s) of a system of linear inequalities give areas of intersection wherein any specific pair of points or lines are solutions.
PROCESS-WISE there are little differences between solving systems. However, multiplication and division by negatives reverses the signs in inequalities.
