Can someone elaborate the rule of common denominators? a) What is 38+14? b) What is 312−215?

Question

Can someone elaborate the rule of common denominators?  a) What is 38+14?  b) What is 312−215?

bubble53zjr · Accepted Answer

Step 1  a) We can see that the denominators are not common. We can also see that the denominator 4 ca become 8 by myltiplying 12 by 22  38+14×22  Simplify  38+28  Now add the fractions.  38+28=58

Vaughn Bradley · Accepted Answer

Step 1b) In this example, the denominators are not multiples of each other, so we must first determine the least common denominator (LCD) of  12 and 15. List the multiples of 12 and 15. The lowest number they have in common is the LCD.12:12,24,36,48,60,72,84⋯15:15,30,45,60⋯The LCD is 60.Now go back to the question.312−215Now we must multiply each fraction by a fractional form of 1 that gives them a denominator of 60.12×5=6015×4=60Multiply each fraction by the appropriate fractional form of 1.312×55−215×44Simplify.1560−860Simplify.760Since 7 is a &#039; number, 760 cannot be reduced.

Can someone elaborate the rule of common denominators? a) What is

Answered question

Answer & Explanation

New Questions in Pre-Algebra