25 points pls hurry im timed Find a b if a = 3i + 8j and b = -0.5i - 4j.

-1.5-32-16ij

Step-by-step explanation:

When you substitute it you will get (3i+8j)(-0.5i-4j)

Then you will use FOIL

From this, you get -1.5-32-16ij

expression #3 is not equivalent. the others are.

38.5

step-by-step explanation:

lets say, first number = r

second number = 3r+7

total = 49

(r)+(3r+7)= 49

4r+7 = 49

4r = 42

r = 42/4

r= 10.5

3r+7 = 3(10.5)+7 = 38.5

hope this