Identify the letter C that would make the trinomial factor able using perfect squares please show your work 26and 28 only

Pls urgent max amount of points will be given and pls do not answer if unsure or you will be reported by me and brainliest answer gets the brainliest .. thing so yeh

How is the equation of this circle written in standard form? x2 + y2 - 6x + 14y = 142 a) (x - 3)2 + (y + 7)2 = 200 b) (x+ 3)2 + (y - 7)2 = 200 (x - 6)2 + (y + 14)2 = 142 d) (x+6)2 + (y- 14)2 = 142

3.4a=57.8 what is the the value of a