0

# Write the Equation of a line that passes through (4,7) and has slope of -3/4

I have to write the slope, and also use point slope to write as my answers

### 2 Answers by Expert Tutors

Vivian L. | Microsoft Word/Excel/Outlook, essay composition, math; I LOVE TO TEACHMicrosoft Word/Excel/Outlook, essay comp...
3.0 3.0 (1 lesson ratings) (1)
0
Hi Andrew;
The point-slope formula is as follows...
y-y1=m(x-x1)
m=slope
Let's plug-in...
y-7=(-3/4)(x-4)
y-7=[(-3/4)(x)]+3
Let's add 7 to both sides of the equation...
7+y-7=[(-3/4)(x)]+3+7
y=(-3/4)x+10

Beth L. | Patient, Knowledgeable and Very Qualified Mathematics TutorPatient, Knowledgeable and Very Qualifie...
-2
Try this:

Slope intercept form is y = mx + b ;  m = slope.

y = -3/4x +b

If it passes through (4,7), plug those numbers in, 4 for x and 7 for y to find b (the constant)

7 = -3/4 (4) + b
7 = -3 + b   Remember -3/4 * 4 = -3/4 * 4/1 (whole number converts to fraction by dividing by 1)

b = 10

y = -3/4 x + 10

Knowing the slope intercept form is faster than figuring it out from the definition of slope.  Slope requires knowing 2 points, not just one.  The slope intercept form is easier to memorize and requires only two pieces of information - the slop and ONE point on the line.