I need to solve using the substitution method, but i can't figure out how to do it with this problem. y^2 mean y squared.
If y^2=x, then you can substitute y^2 for x in the second equation, giving you y^2+2y+3=0. Now that there's but a single variable (y), you should be able to solve as usual for y. Once you have y, plug that number(s) into y^2=x and you'll have x.
The substitution method simply means that, given two equations, one can be reduced into a definitional statement, an equation that just tells you how to express one variable in terms of the other (in other words, an equation that starts with something like "x=" or ends with "=y"). You then substitute whatever's in the complicated side of this equation for the whichever variable is on the simple side in the OTHER equation, at which point you have a normal, one-variable version of the equation.