Answer:
(9 x 0) + 4=4
Step-by-step explanation:
Answer:
15 ways
Step-by-step explanation:

A rectangle has 2 diagonals
To find A' they used the rule of multiplication, which is:
the derivative of a product of two terms is the first term times the derivative of the second term plus the second term times the derivative of the first.
To find b' they just isolated b'
See the image below for a demonstration. Hope this helps out.