Which question are you wanting answered its hard to tell
Answer:
60
Step-by-step explanation:
p = 180 - [ 360 - ( 130 + 110 ) ]
= 180 - [ 360 - 240 ]
= 180 - 120
p = 60
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'