really need help with this question please!!

Question

determine the value for n

a) n/7=2.5/9

b) n+1/3=2n/5

Answer 1

(a)

n/7 = 2.5/9

Multiply both sides by 7 and get

n = 7(2.5/9) = ?

(b)

Not sure if you meant to say

n + 1/3 = 2n/5

or

(n + 1)/3 = 2n/5

Clarify which one you meant, and I will work the solution for you.

Answer 2

Hello, please see below!

We are working with proportions here, so we must check to see if we can simplify any terms, and then cross multiply and use algebra to solve for n.

a)

n = 2.5

7 9

There is nothing here that we can simplify since no factors exist. Let's cross multiply:

9n = 7 (2.5) <--- to avoid ugly decimals, let's make 2.5 into 5/2, its fraction form.

9n = 7 (5/2) <--- 7 x 5/2 = 35/2

9n = 35/2 <--- divide both side by 9 --- 35/2 divided by 9 is like 35/2 x 1/9 = 35/18

n = 35/18

b)

(n+1) = 2n

3 5

Nothing to simplify. Cross multiply:

5(n+1) = 6n <--- distribute 5 to n+1

5n + 5 = 6n <--- subtract 5n from each side

5 = n

n = 5