It is C have a great day luv
Answer: 
Step-by-step explanation:
To solve for b, we want to use the Pythagorean Theorem as given.
b and 7 are the legs, and 12 is the hypotenuse.
[exponent]
[subtract both sides by 49]
[square root both sides]

Now we know
.
Hope this helps with your questions :)
X(7x+3)=0
x=0
or
7x=-3
x=-3/7
so,
(0,0) or (-3/7,0)
You need to get x alone on one side. You need to divide 1/2 on both sides which makes 13 a 26. x<26