How do you solve this problem using substitution and then check it? :
y= -3x-2
2x+5y=16

You have to get a variable by itself like in here... Y is itself so in the other equation or we can say second one you just have to sub it in... Like

2x+5(-3x-2)=16
2x-15x-10=16
Now you just have to subtract 2 from 15, because of the same variable that is (x)
So -13x-10=16
Take 10 to the other side means add from the both sides, that will get you at
-13x=26
So now x= -2
Remember you added because it was -10 if it would be a positive 10 then you have to subtract it from both of the sides but since here it was negative so you just added them up
Hope i helped

We have the variable y so lets substitute
y=-3x-2
2x+5y=16

2x+5y=16
2x+5(-3x-2)=16
2x-15x-10=16
-13x=26
x=-2

y=-3x-2
  =-3(-2)-2
  =4

2x+5y=16
2(-2)+5(4)=16
-4+20=16
16=16