Angle-side-angle is a rule used to prove whether a given set of triangles are congruent. The ASA rule states that: If two angles and the included side of one triangle are equal to two angles and included side of another triangle, then the triangles are congruent
So, to figure out this problem you first need to solve for how much you have left after paying the base fee. Take the total ($84) and subtract by the base fee ($27). You will get 57 as your answer. Then, take $57 and divide it by $0.15 to get your answer. It is 380 minutes each month. The equation here is 84=27+0.15x.
Your answer is y = -(13/3)x + 11/3. I have put the brackets to show that the entire fraction is negative, they do not do anything else.
First we need to find the slope of the line using the equation (y2 - y1)/(x2 - x1), so we get (3/2 - 1/5)/(1/2 - 4/5). To make this easier, I did each subtraction separately:
3/2 - 1/5 = 15/10 - 2/10 = 13/10
1/2 - 4/5 = 5/10 - 8/10 = -(3/10)
And then we need to divide 13/10 by -(3/10), so:
13/10 ÷ -(3/10) = 13/10 × -(10/3) = -(130/30) = -(13/3), which is our slope.
Then, we can write the equation y = -(13/3)x + c, and substitute in coordinates:
3/2 = (-13/3 × 1/2) + c
3/2 = -(13/6) + c
c = 11/3
So the final equation is y = -(13/3)x + 11/3.
I hope this helps!