
Given points are
.
First, find the slope.
\
.
Substitute
2.6 for y2, 0.9 for y1, 3.4 for x2, and 0.6 for x1 in slope formula.

(Subtract:
)
(Subtract:
)
(Divide:
)
You know the slope and a point on the line, so use point - slope form 
with either given point to write an equation of line.
\Choose 
(Substitute 0.9 for y1, 0.6 for x1 and
)
(Apply distributive property:
)
(Multiply:
)
Apply addition property of equality: If a = b then a + c = b + c.
(Add 0.9 to each side)
(Apply additive inverse property:
)
(Apply additive identity property:
)
(Add:
)
The equation of line is
.