The answer is d= -2an+2s/n^2-n
That answer should be in a fraction form.
Answer:
∠MPQ ≅ ∠MPR: Reason; Corresponding parts of congruent triangles are congruent (CPCTC)
∠PQR ≅∠PRQ: Reason; CPCTC
Step-by-step explanation:
: Reason; Given
Draw 
so that M is the midpoint of 
: Reason; Two points determine a line
: Reason; Definition of midpoint
: Reason; Reflexive property
ΔPQM ≅ ΔPRM: Reason; Side Side Side (SSS) rule for triangle congruency
∠MPQ ≅ ∠MPR: Corresponding parts of congruent triangles are congruent CPCTC
∠PQR ≅∠PRQ: CPCTC
12 can only go into 30 about 25 whole times.
Assuming that the cost per minute is the same for both months and the plan fee is the same, you can use y=mx+b for this
y is the cost of the phone plan, x is the cost per minute and b is the start cost.
so 19.41=25x+b for the first month
and 45.65=380x+b for the second month
solve both for b you get:
19.41-25x=b and 45.65-380x=b. from this we get
19.41-25x=45.65-380x
solve for x
328x=26.24 and x=0.08
this means the cost per minute is 0.08c/min (answer A)
rewrite the equation to calculate b, and where this time, the x is the number of minutes talked.
y=0.08x+b and plug in one of the two months
45.65=0.08 * 380 + b
Solve for b and b is 15.25
so the final equation is
y=0.08x+15.25 (answer B)
