Need with part b. is part a 140 times?

1680, and No

Step-by-step explanation:

Part A: A mockingbird beats its wings 420 times per 30 seconds (half a minute). This means that a mockingbird will beat its wings 840 times per minute. Multiply this by two and you get 1680 times in two minutes.

Part B: Divide the amount of beats in a minute by 60 (because there are 60 seconds in a minute) and you get the amount of times a mockingbird beats it wings per second.

420/30 = 14 times per second

Ariel said it was 0.07 times per second which is incorrect.

x = -4

step-by-step explanation:

- 20 - 4(x + 3) = 4x

=> -20 - 4x - 12 = 4x

=> - 32 -4x = 4x

=> -32 = 4x + 4x

=> - 32 = 8x

=> -32/8 = x

=> -4 = x

=

x=0.8898305 is the answer to that equation