Horatio sanded a dresser for 1 1/4 hours. then he stained the dresser for 2 1/3 hours. for numbers 15.a- 15c, select true or false for each statement.

15a. a common denominator of the mixed numbers is 12. ( true or false)

15b.the amount of time spent sanding the dresser can be rewritten as 1 3/12 hours. (true or false)

15c. horatio spent 1 1/6 hours longer staining the dresser than sanding it. (true or false)

  a: true; b: true; c: false

Step-by-step explanation:

The common denominator of the fractions 1/3 and 1/4 can be 12. 15a is true.

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1/4 = 3/12, so 15b is true.

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The difference 2 1/3 -1 1/4 is the difference 2 4/12 - 1 3/12 = 1 1/12. This is not the same as 1 1/6. 15c is false.

Step-by-step explanation:

4x + 6 + 3x + 21 = 8x + 7

7x + 27 = 8x + 7

-x + 27 = 7

-x = -20

x = 20

m<3= 8(20) + 7

         160 + 7 = 167

m<1= 4(20) + 6 = 80 + 6 = 86

m<2= 3(20) + 21 = 60 + 21 = 81