The exterior angle at the intersection of the tangent and secant has a measure that is half the difference between the intercepted arcs.
... ((10x+20) -80)/2 = 2x+15
... 5x -30 = 2x +15
... 3x = 45
... x = 15
So, the unknown arc to the right has measure
.. 10x + 20 = 10·15 +20 = 170
And the arcs of the circle total 360°.
... 80 + z + 170 = 360
... z = 360 - 250 = 110 . . . subtract 250 from both sides
The appropriate choice for the value of z is
... B. 110
Answer:
a) About 48 of the shoppers, that is
of the shoppers, received a free set of earbuds.
b) About 58 shoppers, that is
received $5 off their first purchase.
Step-by-step explanation:
a. About how many shoppers received a free set of earbuds?
21% out of 230. So

About 48 of the shoppers, that is
of the shoppers, received a free set of earbuds.
b. About how many shoppers received $5 off their first purchase?
25% out of 230, so:

About 58 shoppers, that is
received $5 off their first purchase.
The sixth graders collected $250 of their $300 goal. The seventh graders collected $250 of thier $450 goal.
Sixth Graders:
$250 / $300
Reduce: $25 / $30 = 5/6
Seventh Graders:
$250 / $450
Reduce: $25 / $45 = 5/9