Determine if the following sequence is geometric
a) 5,2,-1,-4

b) 5,10,20,40

A) No. It is an arithmetic sequence because you are subtracting by 3.

B) Yes. It is a geometric sequence because you are multiplying by 2.

Step-by-step explanation:

Arithmetic is addition or subtraction.

5 - 3 = 2    2 - 3 = -1    -1 - 3 = -4

Geometric is multiplication.

5 X 2 = 10    10 X 2 = 20    20 X 2 = 40

21°

Step-by-step explanation:

we know that every single triangle has to equal 180°

we have all 3 angles 90° 34° 35° which equal 159°

so we take 180°-159° and your answer is 21°