a b

- = - = 3, Find a + b
4 5

PLEASE HELP! IT'S DUE IN A LITTLE WHILE!

type your fractions this way:

a/4 = b/5 = 3

then:
a/4 = 3 ---> a = 12
and
b/5 = 3 --> b = 15
finally:
a+b = 12+15 = 27

To find the value of a + b, we need to solve the equation:

a/4 = b/5 = 3

The equation means that a divided by 4 is equal to b divided by 5, and both of these fractions are equal to 3.

To find the common value of a and b, we can set up a proportion:

a/4 = b/5

Cross-multiplying, we get:

5a = 4b

Now we can solve for a in terms of b:

a = (4b)/5

Substituting this value of a into the equation a + b = 3, we get:

(4b)/5 + b = 3

To simplify the equation, we can get rid of the fraction by multiplying both sides of the equation by 5:

5 * [(4b)/5] + 5 * b = 5 * 3

This cancels out the fractions and gives us:

4b + 5b = 15

Combining like terms, we have:

9b = 15

Now we can solve for b by dividing both sides of the equation by 9:

b = 15/9

b simplifies to:

b = 5/3

Substituting this value of b into the equation a = (4b)/5, we get:

a = (4 * (5/3))/5

Simplifying further:

a = 20/15

Which simplifies to:

a = 4/3

Therefore, a + b = (4/3) + (5/3) = 9/3 = 3