Help me answer Task 1. D & C, and Task 2. A & B! I will mare brainliest to the best answer

Students are given 3 minutes for each multiple-choice question and 5 minutes for each free-response question on a test. there are 15 questions on the test, and students are given 51 minutes to take it.how many multiple-choice questions are on the test?

The triangles are similar. what is the value of x? show your work.

Which shows the correct substitution of the values a,b and c from the equation 1=-2x+3x^2+1