Write the equation of the line that contains the given point and has the given slope. (15, 31), slope is 0.5

Lets start with the slope intercept form to help find b using the slope given and the point given.

y=mx+b
(31)=.5(15)+b    substitution
31=7.5+b
31-7.5=7.5-7.5+b    additive inverse
23.5=b

Now we can substitute in the slope that was give m=.5 and the y-intercept(b) we found b=23.5:

y=.5x+23.5 (this is your answer)

Y=mx+b   m- slope b- y-intercept(where the line crosses the y axis)
31=.5(15)+b plug in your values
31=7.5+b simplify
23.5=b    subtract 7.5 from both sides and your given b
y=.5x+23.5 plug everything into slope intercept form (y=mx+b)