What is 2x-3y=-1
y=x-1

(4, 3)

Step-by-step explanation:

Let's use substitution.

So for y in the first equation we will substitute the expression for y in the second.

2x - 3(x-1) =  -1

2x -3x + 3 = -1

-1x + 3 = -1

       -3    -3

-1x = -4

-1x / -1 = -4 / -1

x = 4

Now plug in x for the second equation

y = 4 - 1

y = 3

Now check it using the first equation:

2(4) - 3(3) = -1

8 - 9 = -1

-1 = -1

It's true so it's correct

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is: