Simultaneous Equations - Higher 9-1

Now, let us say that in the exam, you get the question:

Solve the simultaneous equations                                               [5 Marks]

y = x² − 6x − 20

y = 4 − x

Now, don't go off in a panic. For these quadratic simultaneous equations, a simple method can be used. 

As you may notice, both of these equations equal 'y'. Due to this, you can say that both equations are equivalent to one another. 

You then write them in the form:

 x² − 6x − 20 = 4 − x

 There is now an equals sign showing that they are equivalent to each other. That is one mark gained.

You then need…