how wouls u solve this

y=x+4

x^2+y^2=16

the questions says:

solving a liner-quadratic system involves finding the values which satasfy a liner equation and a quadratic equation simultaneously. The method of substituting the inear equation into the quadratic equation should be used. The quadratic equation could b a parabola or a circle or any of the conic sections. The values found in the solution represent the co-ordiantes of the point(s) of intersection of the two graphs.

solve the set of real numbers.

can you show me how to do this and explain the steps please