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40 votes
40 votes
Can someone help me i keep getting different answer!!

Can someone help me i keep getting different answer!!-example-1
User Nick Matteo
by
2.6k points

1 Answer

14 votes
14 votes

Answer:

The second option: 3 (6 - 5n)/20n

Explanation:

Make sure all fractions have a common denominator:

Step 1. Find a common multiple between all three denominators

5, 4, and 10 all have a common multiple of 20. Proof: 5 × 4 = 20, 4 × 5 = 20, and 10 × 2 = 20

Step 2. Multiply the denominators to get to 20. Whatever you do to the bottom (denominator) must be done to the top (numerator).

1/5n × 4/4 = 4/20n

3/4 × 5n/5n = 15n/20n

7/10n × 2/2 = 14/20n

Your fractions now all have a common denominator of 20n.

Rewrite the equation using the new fractions:

4/20n - 15n/20n + 14/20n

Only focus on adding/subtracting the numerators; the denominators will stay the same: 20n.

(4 - 15n + 14)/20n

Combine like terms:

(18 - 15n)/20n

Factor out any numbers possible:

3(6 - 5n)/20n

Note* 3 go into both 18 and 15, which allows us to factor 3 out. 18 ÷ 3 = 6 and 15 ÷ 3 = 5, giving us our new numbers inside the parentheses.

User GuillermoMP
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2.9k points