how do I solve Log 21 base 7=x+1?

Answer 1

Log(7) 21 =x+1
Log(7)[7*3 ] =x+1
Log(7) 7+Log(7) 3 =x+1
1+Log(7) 3 =x+1
x=Log(7) 3

Answer 2

bear in mind that logarithms allow you to "replace" multiplcation to addition, and branch to subtraction; additionally variations exponentiation to multiplication. additionally notice that for the reason that a logarithm is an exponent, log base 2 (2) = a million, log base 6 (6) = a million, and specially for this situation log base 5 (5) = a million. Now resolve the situation: log base 5 of (x+ 7 ) = a million - log base 5 (x+3) or, a million - log base 5 (x + 3) = log base 5 of ( x + 7) [rearrange] or, a million = log base 5 (x + 7) + log base 5 (x + 3) [rearrange] or, log base 5 (5) = Log base 5 [(x + 7)*(x + 3)] [ convey a million as a logarithm] or, x^2 + 10x + 21 - 5 = 0 [do away with logarithms, multiply tactors, rearrange] or, x^2 + 10x + sixteen = 0 or, (x + 8)(x + 2) = 0. So, suggestions are x = -8 and x = -2

Answer 3

did you meant log(base 7) (21) = x + 1 ?

if so just subtract 1 for both sides

x = log(base 7) (21) - 1

Answer 4

6

Answer 5

x= 6

7 = 6+1

Answer 6

Why don't you ask Mr. Jones in class tomorrow? Caught ya. I won't say anything, but that is quite a coincidence isn't it?

Would that be question 3 that is really question 4, look closely and wonder, who is this on-line?

These guys don't know what they are doing, the answer is not here.

Don't freak, I'm not him. You are very resourceful.

Answer 7

7^(x+1)=3.7

7^x . 7^1=3.7

7^x = 3.7 / 7

7^x = 3

xln7=ln3

x=ln3/ln7