Question

If LCM of two prime numbers a and b (a>b) is 783 , then the value of 2ab-3a is?​

Answer 1

The value of 2ab-3a is 1479.

Given :

LCM of two prime numbers a and b (a>b) = 783

To find :

The value of 2ab-3a

Solution :

Since 783 is the L.C.M of two prime numbers,

Hence, 783 = 27 × 29

Since a>b ,

a = 29

b = 27

Putting the values of a and b in 2ab-3a

= 2 (29)(27) - 3(29)

= 2 × 783 - 87

= 1566 - 87

= 1479

Hence, the value of 2ab-3a is 1479.

#SPJ3

Answer 2

Complete question:

If the LCM of two co-prime numbers a and b (a>b) is 783, then the value of 2ab-3a is?​

Answer:

The value of 2ab-3a = 1479.

Step-by-step explanation:

Given,

The LCM of two co-prime numbers a and b = 783

To find,

The value of 2ab-3a

Solution:

Recall the concept:

The LCM of two co-prime numbers is equal to product the of the numbers.

Since 783 = 27× 29

The two numbers whose LCM is 783 are 27 and 29.

Since a >b, we have a = 29 and b = 27

then, 2ab - 3a = a(2b -3 )

Substituting the value of a = 29 and b = 27 we get

= 29(2×27 -3)

= 29(54 -3)

= 29 × 51

= 1479

The value of 2ab-3a = 1479.

#SPJ2