Simplify 2/5 + 1/3 on mathswatch
Answers
Answer:
9
10
Step-by-step explanation:
You need a 'common denominator': the number at the bottom of each fraction must be the same. To get that, we can multiply a fraction by
x
x
, where
x
is any number, since
x
x
=
1
.
Since our denominators are 2 and 5, we need a common denominator that both of those will divide into equally. I'm going to choose 10. It's true that 20 or 100 or 1 000 000 would also work, but we usually try to use the 'least common denominator' or 'lowest common denominator' (both are abbreviated as LCD).
To get
2
5
to have 10 as the denominator, I will multiply it by
2
2
, and get
4
10
. (we've really just multiplied it by 1, since
2
2
=
1
)
To get
1
2
to have 10 as the denominator, I will multiply it by
5
5
, and get
5
10
.
Now we can add the two fractions:
4
10
+
5
10
=
9
10
.
We can't simplify that any further, so
9
10
is our answer.