Answer:
a) v = 0
b) b = 7 / 6
c) a = any number
Step-by-step explanation:
a) 7(2+5v)=3v+14
7 x 2 + 7 x 5v = 3v + 14 .... distributive
14 + 35v = 3v + 14
35v - 3v = 14 - 14
32v = 0
v = 0 ...... only v value can fit
b) -3 (3-6b)=6b+5
-9 + 18b = 6b + 5
18b - 6b = 5 + 9
12b = 14
b = 14 / 12 = 7 / 6
c) 2 (a-2)=2a-4
2a - 4 = 2a - 4
2a -4 + 4 = 2a -4 + 4
2a = 2a
a = a ........ a cab be any number
Using the product rule
xCos(y)dy/dx + sin(y) + ycos(x)+sin(x)dy/dx = 0
xcosydy/dx + sin(x)dy/dx = -sin(y) - ycos(x)
(xcos(y) + sin(x))dy/dx = -sin(y) - ycos(x)
dy/dx = [-sin(y) - ycos(x)]/ {xcos(y) + sin(x)}
Margo is correct since each girl got 7 pens and 9*7=63
I hope this helps
5,630,000,000 is the rounded answer.