Calculate the slope k of a straight line passing through two given points М1 (-3; 1), М2 (7; 8)

Let’s write the equation of the straight line in general form: y = kx + b;

Substitute the x and y values ​​at the given points:

for point М1: 1 = k * (-3) + b;

for point М2: 8 = k * 7 + b;

Since both of these points lie on one straight line, the resulting equations must be fulfilled simultaneously, which means you can write the system:

{-3k + b = 1;

{7k + b = 8.

Instead of the {, you must write one large curly brace that joins both equations.

Let’s solve it by the subtraction method: 7k + b – (-3k) – b = 8 – 1;

10k = 7;

k = 0.7.

Answer: the slope of a straight line passing through two given points M1 (-3; 1) and M2 (7; 8) is equal to k = 0.7.