What is 400+20??? i already know what is

40020

Step-by-step explanation:

PLEASE GIVE ME BRAINLIEST I NEED ONE MORE AND I CAN RANK UP

420

Step-by-step explanation:

Well, you said so, and also here is the explanation:

400

+20

420

I don't know if I can have branliest you can give me it if you want

490mph and 510mph

Step-by-step explanation:

Let x mph and x+20 mph be the speeds of the planes. The rate at which their distance from each other increases will be the sum of their speeds which is 2x+20 mph.

Their distance from each other after three hours is ( 1.5 hours)*(2x+20 mph) = 3x+30 miles. We are given that this is 1500 miles so we can solve for x.

3x+30 = 1500

3x = 1500 - 30

3x = 1470

x = 1470/3

x = 490mph

For the second jet :

x +20 = 490+20

x = 510

Thus the speeds of the two planes are 490 mph and 510mph.