Answer:
y = - 3x - 7
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Here m = - 3, then
y = - 3x + c ← is the partial equation
To find c substitute (- 2, - 1) into the partial equation
- 1 = 6 + c ⇒ c = - 1 - 6 = - 7
y = - 3x - 7 ← equation of line
She can find out answer by dividing 21÷3 and the answer is 7
She can make 7 bird house
