Find the area of the isosceles triangle formed by the vertex and the x-intercepts of the parabola y=-x^2-4x+21

Someone answer asap for ! the total ticket sales for a high school basketball game were $2,260. the ticket price for students were $2.25 less than the adult ticket price. the number of adult tickets sold was 230, and the number of student tickets sold was 180. what was the price of an adult ticket?

What is the value of x in the equation 1.5x+4-3=4.5(x-2)?

Find the value of x to the nearest tenth.