Circle O has tangent AB and secant AC as shown. Arc BC measures 4x + 20. Arc BE
measures 2x - 10. Which is the correct way to set up the equation if you are trying to find the value of x?

Multiple choice:

a) 50=0.5(2x-10 - (4x+20)
b) 50=0.5(2x - 10 + 4x + 20)
c) 50=0.5(4x + 20-(2x - 10))
d) 50=0.5(4x +20 - 2x - 10)

Please help!

Ascientist has 50 grams of a radioactive element. the amount of radioactive element remaining after t days can be determined using the equation (1) after two days the scientist receives a second shipment of 50 grams of the same element. the equation used to represent the amount of shipment 2 remaining after t days is 10) - 50 which of the following is an equivalent form of the expression for the amount remaining in shipment 2? what’s the answer?