To find slope you do y2-y1 over x2-x1. So 4-6 is -2. And 3-1 is 2. So -2/2 is -1. The slope is -1.
To find the slope you use the equation:
m = (y₂-y₁) ÷ (x₂-x₁)
You plug in the two points into this equation to find m (m is the slope)
m = (1 - 0) ÷ (0 - 2)
m = 1 ÷ (-2)
m = - 1/2
Next you use this equation:
y = mx + b
Because you know m you plug it in.
y = -1/2x + b
Now you need to find b. To do so you plug in either of the points into this equation(you come out with the same answer for b)
y = -1/2x + b
1 = -1/2(0) + b
1 = b
Finally you plug in b and you get your new equation.
y = -1/2x + 1
It looks like the first and the third are diagrams of similar triangles, and the third needs another right angle marker at E to be persuasive. So I'll go with
First diagram
We're given a congruent angle pair and we have another from vertical angles, so AA, similar triangles.
