Answer :
Question: the line that passes through the point (-1,4) and point (6,y) has a slope of 5/7. find y.
Solution:
By definition, the slope of a line is given by the formula:
[tex]m\text{ = }\frac{Y2-Y1}{X2-X1}[/tex]where m is the slope of the line and (X1,Y1), (X2,Y2) are any two points on the line. In this case, we have that:
(X1,Y1) = (-1,4)
(X2,Y2) = (6,y)
m = 5/7
thus, replacing the above data into the slope equation, we get:
[tex]\frac{5}{7}\text{= }\frac{y-4}{6+1}\text{ }[/tex]
this is equivalent to:
[tex]\frac{5}{7}\text{= }\frac{y-4}{7}\text{ }[/tex]By cross-multiplication, this is equivalent to:
[tex]\text{5 = y-4}[/tex]solving for y, we get:
[tex]y\text{ = 5+ 4 = 9}[/tex]then, we can conclude that the correct answer is:
[tex]y\text{ =9}[/tex]