Hi there! The answer is -2.
We can find the slope of a formula by using the following formula:

x2 and y2 don't mean squared, but the x and y coordinate of our second point.
First we need to find two points on the line. Ijn this particular case we have (-3, 3) and (1, -5). Now we can fill in the formula.

Therefore, the third answer is correct.
~ Hope this helps you!
Let us start with the unknown. Let us give one of the base angles the
value of x. The other base angle is also x since both the base angles in
an isosceles triangle will be equal. The remaining angle is 40 more
than three times one of the base angles.It is 3x + 40. Here we get the
equation
x+x+3x+40=180
5x + 40 = 180
5x = 180 - 40 = 140
Therefore x = 140/5 = 28
So the angles are 28, 28 and 124.
The third angle is 3 times 28 + 40 = 84 + 40 = 124.
Answer:
18
Step-by-step explanation:
15 x 2 = 30
30 - 12 = 18
18 girls are in his class