Can someone please help me?

A

Step-by-step explanation:

it takes 45 hours to plant 100 trees, so his rate is 100/45 trees per hour.

and it takes rose 40 hrs to plant the 100 trees, so her rate is 100/40 trees per hour

So add those together to get (100/45+100/40)

and then multiply them by P(which is in hours) to equal 100

(100/45+100/40)p=100

then divide by 100 both sides to get

p/45+p/40=1

i will u if u answer my question in math

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.