Question

2. IF (18 - x), 5, (15 + x) and 10 are in proportion, then find the value of re​

Answer 1

Answer:

Given : If 2,5,x are in proportion.

To find : The value of 'x' ?

Solution :

If 2,5,x are in proportion i.e. 2:5:5:x2:5:5:x

We know,

Product of extremes = Product of means

i.e. b^2=acb

2

=ac

Here, a=2, b=5 and c=x

Substitute,

5^2=2x5

2

=2x

25=2x25=2x

x=\frac{25}{2}x=

2

25

x=12.5x=12.5

therefore answer is 12.5

Answer 2

Answer:

the value of 'x' is 7

Step-by-step explanation:

given that :

(18-x) , 5, (15+x) and 10 are in proportion

according to proportion,  a:b :: c:d

⇒ (a/b) = (c/d)

⇒ let a = (18-x)

b= 5;

c=(15+x)

d=10

let's apply the formula,

a:b::c:d

⇒(a/b)=(c/d)

⇒(18-x)/5=(15+x)/10

⇒(18-x) = (15+x)/2

⇒ (2)(18-x) = (15+x)

⇒ 36 -2x = 15+x

⇒ rearrange:

⇒ 36-15 = x+2x

⇒21 = 3x

⇒x = (21)/3

⇒ x =7;

the value of 'x' is 7