Question

31. Write the equation of a linear line that is parallel to f(x)= -2x +5 through (-1,4)​

Answer 1

`y=-2x+b`

Explanation:

The equation of the given line is in slope-y_intercept form, so it is easy to see that the slope is "-2".

A parallel line to it should have the same slope. Therefore, it should have the form:

`y=-2x+b`

In order to determine the appropriate value of "b", we use the information that should pass through the point (-1,4) on the plane. That is when x = -1, the y-value must be "4".

We include this condition in the tentative equation of the parallel line we found above, and then solve for "b":

`y=-2x+b\\4 = -2 (-1)+ b\\4=2+b\\4-2 = b\\b=2`

Therefore, the equation of the parallel line is:
`y=-2x+b`