How do you subtract one third minus two thirds?

What are Spain's birth and death rates? Is -1/4 equal to -9/36? What is 139 rounded up to in hundreds? Do irregular shapes have symmetry? How can you write 84.386 in words? What does XLVIII mean in roman numbers? What times what equals to 13? How do you find an area of a hut? What is the perimeter and area of a triangle when a length between its angles of 55 degrees and 48 degrees is 5cm? One hundred three million five hundred eighty-six standard form? What is radius of curvature of spherical surface? The sum of two positive numbers is 53 Find a function that models their product P in terms of x one of the numbers? 3d plus 8 equals 2d-17? What is the opposite of 'divine'? What is 1 tenth of 64? How many 1x8x10' boards would it take to cover an area 10' long by 10' wide? What is the answer for 6pt equals blank fl oz? Could a negitive number be rational? What is 3/4 of a million? What is the dimension of universal gravitational constant?