Step-by-step explanation:
To check if a solution is extraneous, simply plug it back into the original equation. If it works, then solution isn't extraneous.
√(2x−1) = 7
√(2(25)−1) = 7
√(50−1) = 7
√(49) = 7
7 = 7
So the solution isn't extraneous.
The square root of x equals ten is 5
Answer:
B. 
Step-by-step explanation:
The given quadratic trinomial is;

Comparing this to
, we have a=5,b=17,c=6.

Two factors of 30 that add up to 17 is 15 and 2.
We split the middle term to obtain;

We factor by grouping;

Factor further

The correct answer is B.
1km = 1000m
1hr = 3600sec
Do proportions:
1km / 1000m = 15km / x
15000m = x
1hr = 3600sec
15000/3600 = 4.2m per second
Choice 4
If the two quadrilateral are congruent, then ABCD = PQRS is the correct congruence statement.