ABC is an isosceles triangle of vertex A. D is the symmetric of A with respect to (BC) and E the symmetric of A with respect to B

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

Which best explains why this triangle is or is not a right triangle ?