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Solve (with steps please)

7^(2+x)=49*7^(2x)

 Sep 13, 2015

Best Answer 

 #2
avatar+130516 
+5

7^(2+x)=49*7^(2x)      and we can write

 

7^2 * 7^x  = 7^2 * 7^(2x)      divide both sides by 7^2

 

7^(x)  = 7^(2x)       and since the bases are the same, we can solve for the  exponents

 

x = 2x         subtract x from both sides

 

0 = x

 

 

cool cool cool

 Sep 13, 2015
 #1
avatar
+5

Solve for x over the integers:
7^(x+2) = 7^(2 x+2)
Take logarithms of both sides to turn products into sums and powers into products.
Take the natural logarithm of both sides and use the identity log(a^b) = b log(a):
log(7) (x+2) = log(7) (2 x+2)
Write the linear polynomial on the left hand side in standard form.
Expand out terms of the left hand side:
log(7) x+2 log(7) = log(7) (2 x+2)
Write the linear polynomial on the right hand side in standard form.
Expand out terms of the right hand side:
log(7) x+2 log(7) = 2 log(7) x+2 log(7)
Isolate x to the left hand side.
Subtract 2 x log(7)+2 log(7) from both sides:
-(log(7) x) = 0
Divide both sides by a constant to simplify the equation.
Divide both sides by -log(7):
Answer: 
x = 0

 Sep 13, 2015
 #2
avatar+130516 
+5
Best Answer

7^(2+x)=49*7^(2x)      and we can write

 

7^2 * 7^x  = 7^2 * 7^(2x)      divide both sides by 7^2

 

7^(x)  = 7^(2x)       and since the bases are the same, we can solve for the  exponents

 

x = 2x         subtract x from both sides

 

0 = x

 

 

cool cool cool

CPhill Sep 13, 2015

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