Question

PLZ HELP!!!

Answer 1

Solution:

The given equation is:

$3^2 x + 7^2= 2 ^x\\\\9 x +49 =2^x$

A: Taking , x=1

L H S = 9 × 1  + 49 = 9 + 49= 58

R H S : $2^x=2^1=2$

L H S ≠   R H S

B: Taking x=3

L H S = 9 × 3 + 49=27 + 49=76

R HS = $2^x = 2^3 = 8$

L H S ≠  R H S

C: Taking x=5

L H S = 9 × 5 + 49

        = 45 + 49

       = 94

R H S:

$2^x=2^5=32$

L H S ≠ R H S

(D)

when , x= 8

L H S

9 × 8 + 49

= 72 + 49

= 121

R HS:

$2^x=2^8 =256$

L H S ≠ R H S

Answer 2

Answer:

(B) x=3

Step-by-step explanation:

The given equation can be written as:

$\frac{3}{2}x+\frac{7}{2}=2^x$

(A) Substituting the value of x=1. we get

$\frac{3}{2}+\frac{7}{2}=2$

$5=2$

which is not possible, therefore x=1 is not the solution of the given equation.

(B) Substituting the value of x=3, we get

$\frac{3}{2}(3)+\frac{7}{2}=2^3$

$\frac{9}{2}+\frac{7}{2}=8$

$8=8$

which is possible, therefore x=3 is the solution of the given equation.

(C) Substiuting the value of x=5, we get

$\frac{3}{2}(5)+\frac{7}{2}=2^5$

$\frac{15}{2}+\frac{7}{2}=32$

$11=32$

which is not possible, therefore x=5 is not the solution of the given equation.

(D) Substituting the value of x-8, we get

$\frac{3}{2}(8)+\frac{7}{2}=2^8$

$\frac{31}{2}=256$

which is not possible, therefore x=8 is not the solution of the given equation.