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.
Answer:
C
Step-by-step explanation:
We know it's direct variation using the direct variation equation.

Where k is the constant.
Since 7 times x is the y values, 
Now we can substitute 7 into k of the direct variation equation.

6=S
therefore, to find one you must divide both sides by 6
the answer should be = 1=S/6
You need to do the distributive property first so the answer is C
Answer:
9. a) 180 - (55+90) = a
b) a=35 degrees
10. a) 2w + 3w + 40 = 180
b) w=28
c) 2w=56 3w=84
Step-by-step explanation: