Answer:
c
Step-by-step explanation:
Answer:
us set up the following variables:
⎧
⎪
⎪
⎪
⎪
⎨
⎪
⎪
⎪
⎪
⎩
l
Length of Rectangle (cm)
w
Width of Rectangle (cm)
A
Area of Rectangle (
c
m
2
)
t
Time (s)
We are told that:
d
l
d
t
=
8
cm/s (const), and,
d
w
d
t
=
3
cm/s (const)
The Area of the rectangle is:
A
=
l
w
Differentiating wrt
t
(using the product rule) we get;
d
A
d
t
=
(
l
)
(
d
w
d
t
)
+
(
d
l
d
t
)
(
w
)
∴
d
A
d
t
=
3
l
+
8
w
So when
l
=
20
and
w
=
10
⇒
d
A
d
t
=
3
⋅
20
+
8
⋅
10
∴
d
A
d
t
=
60
+
80
∴
d
A
d
t
=
140
cm
99*(4/3)=x
99*1.333=x
x=132
This week's movie was 132 minutes long, or 2 hours 12 minutes long.
2 1/2 pounds = $18
for 1 pound = How many dollars
1 pound = $18 ÷ 2 1 /2
= 18 ÷ 2.5
= $ 7.2
1 pound = 453.6 grams
so 453.6 grams = $7.2
price of 1 gram = 7.2 / 453.6 = $ 0.0158
The answer is 3150 :)
BODMAS
brackets, division, multiplication, addition, subtraction
