How many intersections do you expect from four straight lines ? Which three lines enclose a triangle with negative co-ordinates for every point ?
Change one equation in this pair of simultaneous equations very slightly and there is a big change in the solution. Why?
Is there a temperature at which Celsius and Fahrenheit readings are the same?
Which is bigger, n+10 or 2n+3? Can you find a good method of answering similar questions?
When I park my car in Mathstown, there are two car parks to choose from. Can you help me to decide which one to use?