Question

A line passes through (4, 5) and (8, 9). Which equation best represents the line?

y = x + 1
y = 1
y = 2x + 1
y = 5x + 8

Answer 1

could you help

Answer 2

The general equation of a line is:
y=ax + b

The points the line passes through must evaluate its equation
thus:
5=a*4 + b and
9=a*8 + b

Solve the system by substracting each sides:

5-9 =4*a -8*a +b -b
-4=-4*a
a=1
Substitute a into one the first equations to find b:
5=1*4+ b
b=1

so the equation of the line is
y=x+1

Answer 3

thank you