I need some help with this question

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?

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?

Write a similarity statement for the similar triangles. afgh ~ a