Answer:
Step-by-step explanation:
The area for a triangle is
[tex]A=\frac{1}{2}bh[/tex]
Our base is given as x, the height is given as 1 more than 6 times the base which looks like this: 6x + 1. We know that the area is 13, so filling in everything:
[tex]13=\frac{1}{2} (6x+1)(x)[/tex]
We can get rid of the denominator of 2 by multiplying it on both sides to get:
[tex]26=(6x+1)(x)[/tex] and simplifying a bit:
[tex]26=6x^2+x[/tex]
Now we can move over the 26 and put the expression into standard quadratic form by setting it equal to 0:
[tex]6x^2+x-26=0[/tex] which is choice C