What is -18-x-x40?

Is 2 hundreds and 4 tens the same as 24 tens? Write the fraction 10 over 26 in simplest form? What is 3 5ths of 187 pounds? How much is 12 of 50 dollars? How do you write 2400 in word form? What numbers multiplied make 120? How do you express 0.465 as percentage? Which countries have constant temperatures between 10 and -10? Which variable usually goes on the vertical axis? Does a trapezoid fit in the convex polygon? What is the number that divides 1200 and five? Calculate the frequency of a wave which has a wavelength of 565nm? How many days are in the month of April? How do you find the volume in cubic feet? Are school signs shaped like a stop sign? 10ml equals how many cm? How do you solve the problem 7 to the 4th power? Why do you multiply and divide functions? What kind of angle will be formed by line ab and line eh if they are extended? Find things associated with the number 11?