Eight *(a number) plus 5*(another number) is -13.
translates to:
8(x) + 5(y) = -13
The sum of (the number) and (the other number) is 1.
translates to:
(x) + (y) = 1
We have a system of two equations involving two unknowns: x and y.

We can easily solve the system using Substitution or Elimination. Let's use Elimination this time.
We'll multiply the second equation by -8 so that the x's match up.

When we add the equations together, the x's will fall out of the equation, summing to zero. The 5y and -8y will sum to -3y and the right hand side will sum to -21.

Divide by -3,

Plug back into one of your original equations to find the value of x,

Subtract 7,
It is 5.5 us pints.........hope it helps
2(7÷10)×1÷3+4÷15=1.4×0.33+0.267
=0.462+0.267
=0.729(0.73)
Okay, this is not really an answer, but I think in 2020, we will be in the 20 trillions. O know that is not the answer you were looking for, but its all I got.