
Given points are 
Next, find the slope.
\
Substitute
4 for y2, 2 for y1, 3 for x2, and
1 for x1 in slope formula.

(Product of two same signs is positive)
(Add:
)
(Subtract:
)
(Simplify) \ \
(Cancel common terms)
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 2 for y1,
1 for x1 and
)
(Product of two same signs is positive)
(Apply distributive property:
)
(Multiply:
)
(Add to 2 each side)
(Apply additive inverse property:
)
(Apply additive identity property:
)
To add fractions the denominators must be equal.
\Find the least common denominator (LCD).
\Write the prime factorization of each denominator.
\

Multiply the highest power of each factor in either number.
\
LCD of the fractions is 2.
\Rewrite the equivalent fractions using the LCD.
\

Rewrite the expression using the LCD.
\
(Add:
)
The equation of line is
.