$\"\"$ $\"\"$

The equation is $\"\"$ .

Apply multiplication property of equality: Multiply each side by negative 2.

$\"\"$

$\"\"$ (Cancel common terms)

$\"\"$ (Multiply: $\"\"$ ) $\"\"$

Apply subtraction property of equality: Subtract 4 from each side.

$\"\"$

$\"\"$ (Apply additive inverse property: $\"\"$ )

$\"\"$ (Apply additive identity property: $\"\"$ )

$\"\"$ (Subtract: $\"\"$ ) $\"\"$

The value of b is 30.