Question

Mary is solving the equation 5^x + 4 =11. her first steps are shown.

step 1. 5^x + 4 =11
step 2. 5^x =7
step3. In5^x=In7


which shows step 4?

A. In 5 = x In 7
B. x In 5 = In 7
C. ^-In 5 = In 7 * x
D. x = In 7 - In 5

Answer 1

Option B. x In 5 = In 7

Explanation:

we have

`5^(x)+4=11`

step 1

`5^(x)+4=11`

step 2

Subtract 4 both sides

`5^(x)+4-4=11-4`

`5^(x)=7`

step 3

Apply ln both sides

`ln(5^(x))=ln(7)`

step 4

`xln(5)=ln(7)`

step 5

Divide by ln(5) both sides

`x=ln(7)/ln(5)`