Question

Have been given a table of values and to complete it using the equation, y = x^2 - 3x + 10.
(-1,14), (0,10), (1,8), (2,?), (3,10), (4,?) and (5,20).
You draw a graph, using 2cm=1 unit on x-axis and 2cm=2 units on y-axis.
Now my question is...how do you solve the simultaneous equations using the graph:
y = x^2 - 3x + 10.
y = x + 7.
Seriously want help here...and explain more clearly

Answer 1

(-1,14), (0,10), (1,8), (2,?), (3,10), (4,?) and (5,20)
the missing values should be like:
(-1,14), (0,10), (1,8), (2,<b>8</b>), (3,10), (4,<b>14</b>?) and (5,20)

Now if you put those same x value into the straight line you get:
(-1,6), (0,7), (1,8), (2,9), (3,10), (4,11), and (5,12)

Notice that (1,8) and (3,10) are in both tables.
so x=1, y=8 and x=3,y=10 are your solutions.

Your graph should look like this

http://www.wolframalpha.com/input/?i=y+%3D+x%5E2+-+3x+%2B+10+,++y+%3D+x+%2B+7