See the attached picture:
Answer:
Average speed = 100 km/h
Step-by-step explanation:
Given:
Total distance covered = 250 km
Total time taken = 8:30 am - 6:00 am = 2:30 hours = 2.5
Find:
Average speed.
Computation:
⇒ Average speed = Total distance covered / Total time taken
⇒ Average speed = 250 / 2.5
⇒ Average speed = 100 km/h
Start with

Add 2x to both sides:

Subtract 21 from both sides:

Divide both sides by 5. Since it is positive, we don't have to change the inequality sign:

So, the answer is 
Answer:
The integers are 4 and 7 or -2 and 1.
Step-by-step explanation:
You can make a system of equations with the description of the two integers.
1. x = y + 3
2. 2x + 2 = y^2
The simplest and the fastest way to solve this system in this case is substitution. You can substitute x for y + 3 in the second equation.
1. x = y + 3
2. 2(y + 3) + 2 = y^2
Now simplify and solve the second one. For convenience, I will just disregard the first equation for now.
2y + 6 + 2 = y^2
y^2 - 2y - 8 = 0
You can factor this equation to solve for y.
(y - 4) (y + 2) = 0
y = 4, y = -2
Now we can substitute the value of y for x in the first equation.
x = 7, x = 1