The answer is :
c. (x+1)²=20
To check:
(x+1)²=20 (a+b)²=a²+2ab+b²
x²+2x+1=20
x²+2x=20-1
x²+2x=19
Applying a dilation centered at the origin with scale factor
has the effect of multiplying both coordinates of a point by
:

So, in your case, the coordinates of the points double:

The inequality is t < 55
<em><u>Solution</u></em><em><u>:</u></em>
Given that, To qualify for the championship a runner must complete the race in less than 55 minutes
Let "t" represent the time in minutes of a runner who qualifies for the championship
Here it is given that the value of t is less than 55 minutes
Therefore, "t" must be less than 55, so that the runner qualifies the championship
<em><u>This is represented by inequality:</u></em>

The above inequality means, that time taken to complete the race must be less than 55 for a runner to qualify
Hence the required inequality is t < 55
Answer:
distance covered in 2 hours = 80 km
distance covered in 1 hour = 80÷2 = 40 km
distance covered in 7/2 hours = 40 × 7/2
= 140 km
(3 1/2hours = 7/2 hours)