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If 3a+4a=14, and b+6b=21, then 7(a+b) =

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User Quornian
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2 Answers

5 votes
3a+4a=14 well we are combining terms so 3a and 4a will be 7a=14. Now we have an equality so we isolate the variable to give a the answer of 2. Then for b+6b=21 we do the same and combine terms having 7b since the single b there will always be a 1. Then we isolate the variable Again getting 3 for a. Lastly for 7(a+b) you have to disturb a and b with 7 which means (7*2)+(7*3)=14+21=35
User DiRiNoiD
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4 votes
Hello!

You have to find what a and b are

3a + 4a = 14
b + 6b = 21

Lets do a first

3a + 4a = 14

Combine like terms

7a = 14

Divide both sides by 7

a = 2

Now lets do b

b + 6b = 21

Combine like terms

7b = 21

Divide both sides by 7

b = 3

Put a and b into the third equation

7( 2 + 3) =

Do what is in parenthesis first

7(5) =

Multiply

35

The answer is 35

Hope this helps!
User Jeet Dholakia
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5.2k points