Question

what number should be added to each of the number 5,9,7,12 which are in proportion

Answer 1

Answer:

Step-by-3step explanation:

Let the number be x

Then, $\frac{5+x}{9+x\\}$ = $\frac{7+x}{12+x}$  because they are in proportion.

So,(5+x)(12+x) = (7+x)  (9+x)

So, x² +17x + 60 = x² +16x + 63

=> 17x - 16x = 63- 60

=> x = 3

So,3 should be added