This is for 20 !
the cost of having photos taken includes a sitting fee and $12 for each portrait. the cost of 3, 6, and 9 photos respectively is $51, $87, and $123. what is the sitting fee?
a. $13
b.$15
c.$27

All really need to do is pick one number. so, we will go with 6 and 87.

6 times 12 is 72 then you subtract that from $87.

That would be 15

To double check, you can use another one. 9 and 123.

9 times 12 is 108. subtract that from 123 and you get 15.

Your answer is B) $15

Hope I helped :)

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq