Exercise 67 Page 533

When adding or subtracting fractions, they should have the same denominator. In this exercise, we have two fractions with different denominators. 11/12 - 7/45Since 45 is not an integer multiple of 12, we need to find the least common multiple of the denominators. In our case, it is 180. Let's now multiply both denominators by, respectively, 15 and 4 to obtain a common denominator.

11/12-7/45

ExpandFrac

a/b=a * 15/b * 15

11*15/12*15-7/45

ExpandFrac

a/b=a * 4/b * 4

11*15/12*15-7*4/45*4

Multiply

Multiply

165/180-28/180

Now that we have a common denominator, we can proceed to simplifying the expression.

165/180-28/180

SubFrac

Subtract fractions

165-28/180

SubTerm

Subtract term

137/180