Question

The point A(0,3) and point B(4,19) lie on the line L. Find the equation of line L

Answer 1

Answer:  The equation is   y = 4x+3

Slope = 4

y intercept = 3

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Explanation:

Let's start off by finding the slope.

$A = (x_1,y_1) = (0,3) \text{ and } B = (x_2,y_2) = (4,19)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{19 - 3}{4 - 0}\\\\m = \frac{16}{4}\\\\m = 4$

The slope is 4.

The y intercept is 3 because of the point (0,3)

We go from y = mx+b to y = 4x+3

m = slope

b = y intercept

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Check:

Plug in x = 0 and we should get to y = 3

y = 4x+3

y = 4(0)+3

y = 0+3

y = 3

That works out. Now try x = 4. It should lead to y = 19

y = 4x+3

y = 4(4)+3

y = 16+3

y = 19

The answer is confirmed.