Which sum does the model below represent?
+ + + +
- - - - - - -
4+ (-7) = -3
4+ 7 = 11
8+(-3) = 4
11+ (-4) = -3

Henry is an avid reader, he devours 90 pages in half an hour how many pages has henry read per minute?

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.

Look at the figure below: triangle abc is a right triangle with angle abc equal to 90 degrees. the length of ac is 5 units and the length of ab is 4 units. d is a point above c. triangle adc is a right triangle with angle dac equal to 90 degrees and dc parallel to ab. what is the length, in units, of segment cd?