Anonymous
Anonymous asked in Science & MathematicsMathematics · 9 years ago

# how do you solve 1/2+8/9-20/30?

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• Sun
Lv 7
9 years ago

1/2+8/9-20/30,

20/30=2/3,

1/2+8/9-2/3,

9/18+16/18-12/18,

9+16-12=13,

13/18.

• 9 years ago

to solve this you need to make the denominators the same.

we can make all of the denominators 18.

so 1/2 * 9/9 = 9/18

8/9 * 2/2 = 16/18

20/30 is the same as 2/3

so 2/3 * 6/6 = 12/18

that gives us 9/18+16/18-12/18

25/18-12/18

13/18

1/2+8/9-20/30=13/18

• Anonymous
9 years ago

First, you have to find a common denominator of all three fractions in the equation.

Then, set all the denominators equal to a common denominator (18).

The common denominator was 18 because you could reduce 20/30 to 2/3.

After that, the equation would be changed to 9/18+16/18-12/18.

Then, you would get the answer of 13/18

: )

Source(s): Algebra 1 student
• 9 years ago

take all the denominators to their least common multiple, in this case...there is 2, a 9 and a 30 in denominators respectively.. therefore its being 270 their least common multiple(L.C.M.)...

then multiply the numerators of each term by the number which u use to multiply the denominator to take it to its L.C.M. For an e.g. to make denominator of the first term 270, u shud multiply it by 135..multiply the numerator too by 135. that give u 135/270, similarly multiplying boy numerator and denominator by 30 in the second term gives 240/270 and the third term gives 180/270.

then use the BODMAS method, so first add the terms which u need to add that is 135/270+240/270..that gives u 375/270...then substract..375/270 - 180/270 = 195/270...well well seems we can still simplify it...13/18 ...k thats it

• 9 years ago

by using "BODMAS"

1 - Brackets

2 - Powers

3 - Divisions

4 - Multiplication

6 - Subtraction.

so you do (1/2) + (8/9) - (20/30)

• Mike G
Lv 7
9 years ago

1/2+8/9-2/3 =

[27/54+48/54-36]/54=

39/54 = 13/18