The second term in an arithmetic sequence is 10 and the fifth term is 22. if the first term is a1, what is an equation for the nth term of this sequence?

In an arithmetic sequence, the nth term is the first term + (n-1)* difference
the fifth term=the second term +(5-2)*difference
22=10+3d
d=4
the first term=the second term-the difference=10-4=6
the nth term =6+4(n-1) or  or 10+4(n-2), 

Where m is the slope of the line and b is the y-intercept of the line, or the y-coordinate of the point at which the line crosses the y-axis. to write an equation in slope-intercept form, given a graph of that equation, pick two points on the line and use them to find the slope. this is the value of m in the equation.