At whats points does the graph of (t^2)+8t+7 intersect the x axis

Explain to the students what a one to many functions is which in this case is a quadratic, giving them an understanding of why there are two solutions, aided with the image of the quadratic.
Followed by explaining how to solve the quadratic and obtaining the values of x. In this case showing the fastest method of factorising, however, also explained the quadratic formula for cases that they cannot be factorised