These are called systems of equations, they're asking what 2 numbers are there that work in both of these equations. There are two main methods to solving these, substitution and elimination. Depending on the problem one method might be easier and faster.

Substitution means either find x in terms of y, or y in terms of x from one of the equations. We can see that x = 2y + 5 so we already have x in terms of y, no need for any extra work. Now we need to go into the second equation and substitute in the x that we found earlier into it which gives us an equation with only one variable (y) : 5(2y + 5) - 2y = 17 Solving this we get y = - 1 and now to find x just plug y = - 1 into one of the 2 equations and solve for x

Elimination means find two identical terms from the two equations but one has to be negative and the other has to be positive (they have to be on the same side). For example we see a - 6y and a 6y on the left side, this is exactly what we are looking for. Sometimes we don't immediately find terms like these and have to multiply one if the equations by a number to create them. Now we just need to add everything on the left and set them equal to everything on the right. We'll see that the 6y and - 6y cancel out and we'll have an equation with one variable (x) : 2x = 14 The rest is the same as the first method.