# Math

posted by .

Solve the following exponential equation
5^2-x=7^5x+7

• Math -

5 ^ 2 = 25

7 ^ 5 = 16,807

5 ^ 2 - x = 7 ^ 5 x + 7

25 - x = 16,807 x + 7 Add x to both sides

25 - x + x = 16,807 x + 7 + x

25 = 16,808 x + 7 Subtract 7 to both sides

25 - 7 = 16,808 x + 7 - 7

18 = 16,808 x Divide both sides by 16,808

18 / 16,808 = 16,808 x / 16,808

18 / 16,808 = x

2 * 9 / ( 2 * 8,404 ) = x

9 / 8,404 = x

x = 9 / 8,404

• Math -

If you mean,
5^(2-x) = 7^(5x + 7)
Then, we take the ln of both sides
(2-x)*ln(5) = (5x + 7)*ln(7)
1.609*(2-x) = 1.946*(5x+7)
Solving for x,
x = -0.9174

Hope this helps :3

## Similar Questions

Solve the equation by expressing each side as a power of the same base and then equating exponents. 9^(x - 9)/8= sqrt of 9 i got 13 4^(x + 10) = 8^(x - 6) i got 38 Solve the exponential equation. Express the solution set in terms of …
2. ### exponential equation-Algebra

Solve the exponential equation. Express the solution set in terms of natural logarithms. 4^(x + 4) = 5^(2x + 5)-This question I don't understand.
3. ### Algebra Help

Let x = log_2 1/8 Write the exponential form of the equation and solve the equation for x. Does this work?
4. ### Math - Exponential equation

Solve the exponential equation. Express your solutions in exact form only. Please show all of your work. 5e^(x log(9)) = 11
5. ### college algbra

find the domain f(x)=x/x-8,g(x)=-7/x solve the following exponential equation equation exact answers only 3e x-1 = 2+e^x-1
6. ### math need help urgent

find the domain f(x)=x/x-8,g(x)=-7/x solve the following exponential equation equation exact answers only 3e x-1 = 2+e^x-1
7. ### math need help urgent

find the domain f(x)=x/x-8,g(x)=-7/x solve the following exponential equation equation exact answers only 3e x-1 = 2+e^x-1
8. ### math

solve the following exponential equation e^x-4=-e^-x please show work
9. ### math

solve the following exponential equation e^x-4=-e^-x when I work i get x-In(u) is this correct
10. ### algebra

Solving exponential and logarithmic equation. An example of an exponential equation is: Solve for x: 5^x=125

More Similar Questions