Good morning, can someone help me solve this problem? I already did some of it but I need help, thank you

  (-4, -1)

This means x = -4 and y = -1 pair up together.

You're on the right track. You'll replace the 'x' with 3y-1, but you made a typo. I think you meant to write the subtraction symbol instead of the equal sign.

Here's what your steps could look like

-2x + 5y = 3

-2(3y-1) + 5y = 3

-6y + 2 + 5y = 3

-y + 2 = 3

-y = 3-2

-y = 1

y = -1

x = 3y-1

x = 3(-1) - 1

x = -3-1

x = -4

Therefore, (x, y) = (-4, -1) is the solution

As the steps above show, I replaced each copy of x in the second equation with (3y-1). This is due to x = 3y-1. From there, we isolate y. Once you determine that y = -1, it's plugged into the first equation to find x.

If you were to graph x = 3y-1 and -2x+5y = 3 on the same xy coordinate grid, then the two lines would intersect at (-4, -1)

Also, note how plugging x = -4 and y = -1 into the second equation leads to...

-2x+5y = 3

-2(-4)+5(-1) = 3

8 - 5 = 3

3 = 3

We get the same value on both sides, so that verifies the second equation. I'll let you verify the first equation.

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: