What is -1/5 + 7/10 equal

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

Asurvey of 2,000 doctors showed that an average of 3 out of 5 doctors use brand x aspirin. how many doctors use brand x aspirin

Solve these problems: 1.what is the perimeter of an equilateral triangle with sides measuring 6cm? 2. a regular pentagon has sides measuring 3.2 cm. what is its perimeter? 3. a regular decagon has sides of 3.5mm . what is it’s perimeter? 4. a regular octagon has a perimeter of 64cm. what is the length of one of the sides? 5. a regular hexagon has a perimeter of 72mm . what is the length of one of the sides? 6. what is the perimeter of a rhombus with sides measuring 11m?