Answer:
The answer is C. -336
Step-by-step explanation:
All you have to do is 25 - 39 = -14 x 24 = -336
Hope this helps :)
A + b = 15 ..... eq 1
a – b = 12 ...... eq 2
So a = 15 – b
Substitute in eq 2 :
15 – b – b = 12
15 – 2b = 12
–2b = 12 – 15
b = 1.5
So a = 15 – 3/2 = 13.5
4ab = 4 x 13.5 x 1.5 = 81
Y=ax+b, y=cx+d (a≠0, c≠0)
If the two line cross perpendicularly ⇔ ac= -1
So a tangent of the perpendicular line is "-(1/5)".
Then, the equation of the perpendicular line is y=-(1/5)x+a (a is <span> y-intercept</span>).
On the other hand, this equation pass r(1, 3), so
3 = -(1/5) times 1 + a
∴ a=16 / 5
Therefore, y=-(1/5)x+16 /5 is answer.
By the way, I'm Japanese so if you find some mistakes in my English, please let me know.