Question

Janelle graphed a line through (−6, 5) that had a slope of −79. What is the y-coordinate of a point on the line that has an x-coordinate of 3?

Answer 1

The value of the y-coordinate is -706

Explanation:

The equation of a straight line is;

y = mx + c

where m is slope and c is t-intercept

Given the slope, we can write the equation as;

y = -79x + c

we need to get c

Just put in the x and y values of the given point

X = -6 and y = 5

5 = -79(-6) + c

5 = 474 + c

c = 5-474 = -469

So the complete equation of the line would

be ;

y = -79x - 469

To get the y-coordinate of the point, just insert the x value into the equation;

y = -79(3) - 469

y = -237 - 469 = -706