Answer:
9
Step-by-step explanation:
6+x, when x = 3
6+(3)
6+3=9
If you think of the equation as an equation for a line.
y=mx+b
y
=
m
x
+
b
where
C=5/9(F−32)
C
=
5
/
9
(
F
−
32
)
or
C=5/9F−5/9(32)
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
If you look at the picture, you set it up as part over whole is equal to percent over 100. then you just multiply across.