The graphs of the following equations are drawn:
1 y = 3x – 2
2 y = x2
3 y = 1 – x2
4 y = x + 6
Which pair of graphs do not intersect?

Answer:

16) E

Let x = 1.

Equation 1:
y = 3x – 2
y = 3(1) – 2
y = 1

Equation 2:
y = x²
y = 1²
y = 1 (eq 1 and 2 will intersect) 

Equation 3:
y = 1 – x²
y = 1 – 1
y = 0 (this is pretty close to 1 and 2) 

Equation 4:
y = x + 6
y = 1 + 6.
y = 7 (very far away from all graphs but it is farthest away from eq 3)

The furthest graphs are 3 and 4. You can also notice that since eq 4 has a plus sign, the points will always be much higher than equation 3 since equation 3 has 1 – x². 

Alternatively, you can draw a quick graph to see which equations will intersect. Whatever suits you best!