The ph scale measures how acidic or basic a substance is. bleach is said to have a ph of less than 14 and greater than 11. model the normal range of ph values of bleach, using a compound inequality

The length of a rectangle plus its width is 25 cm. the area is 156 square cm. what are the length and width of the rectangle? separate the answers with a comma.

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

Solve the following pair of equations for x and y: ax/b_ by /a= a +b; ax - by = 2ab