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Directions: Solve these equations by using addition. You will need to use your fraction and decimal skills to solve these

equations.
1) N + 8 = 13
2) B + 17 = 62
3) X + 5/6 = 7/16
4) Y + 1/7 = 5/8
5) 14 + y = 69
6) C + 3.6 = 4.9
7) A number increased by 19 is equal to 221
8) A number increased by 1 2/3 is equal to 8

User Keverw
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1 Answer

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One simple way to approach this is to subtract the number that DOESN’T have the variable with the solution by the sum.
Lets use problem 1 as the example:
1.) N+8=13
In this case, we subtract 13 by 8 and get 5, therefore N= 5.

2.) B+17=62
62-17= 45
B= 45

3.) X+5/6= 7/16
7/16-5/6= -19/48
X= -19/48

4.) y+1/7=5/8
5/8-1/7= 27/56
Y= 27/56

5.) 14+y=69
69-14=55
Y=55

6.) c+3.6=4.9
4.9-3.6=1.3
C= 1.3

Now for the word problems:
Lets use 7 as the example-
7.) a number increased by 19 is equal to 221.
Since we don’t know the number being increased by 19, that will be our variable. It will be re-written as so:

N + 19 = 221

Where N is the unknown number.

Using the same method of subtracting by the sum and the number that’s not the variable, we’ll get the solution to N
221-19= 202
N= 202

8.) N + 1 2/3 = 8
8 - 1 2/3 = 19/3= 6 1/3
N= 6 1/3

I really hope this helps
User Fernando SA
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4.0k points