Write an equation in slope-intercept form for the line that passes through (1,9), and (3,5).

To write the equation of the line, we will use the point-slope formula.

To do this, we need a point and a slope.

We can find out slope by using the slope formula.

m = y₂ - y₁ / x₂ - x₁

So we have 5 - 9 / 3 - 1 or -4/2 which is -2.

Now let's use the point-slope formula.

y - y₁ = m(x - x₁)

Now substitute one of our points (x₁, y₁) into our formula.

So we have y - 5 = -2(x - 3).

Distributing the -2 gives us y - 5 = -2x + 6.

Moving the -5 to the right, we have y = -2x + 11.

So y = -2x + 11 is our equation.

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