Find the Equation Using Slope-Intercept Form m=4 , (7,7)

$m = 4$ , $(7, 7)$

Find the value of $b$ using the formula for the equation of a line.

Use the formula for the equation of a line to find $b$ .

$y = m x + b$

Substitute the value of $m$ into the equation.

$y = (4) \cdot x + b$

Substitute the value of $x$ into the equation.

$y = (4) \cdot (7) + b$

Substitute the value of $y$ into the equation.

$7 = (4) \cdot (7) + b$

Find the value of $b$ .

Rewrite the equation as $(4) \cdot (7) + b = 7$ .

$(4) \cdot (7) + b = 7$

Multiply $4$ by $7$ .

$28 + b = 7$

Move all terms not containing $b$ to the right side of the equation.

Subtract $28$ from both sides of the equation.

$b = 7 - 28$

Subtract $28$ from $7$ .

$b = - 21$

Now that the values of $m$ (slope) and $b$ (y-intercept) are known, substitute them into $y = m x + b$ to find the equation of the line.

$y = 4 x - 21$