Question

log10x+log10(x+3)=1

Answer 1

hint:
\[Log(a)+Log(b)=Log(a*b) \]

Answer 2

so log (x^2 + 3x) = 10?

Answer 3

i mean = 1?

Answer 4

yes

Answer 5

so how would you solve for x ?

Answer 6

x^2+3x=10^1

Answer 7

because \[10^{\log_{10}(x^2+3x) }=10^1\]
and \[10^{\log_{10}(x^2+3x) }=x^2+3x\]

Answer 8

do you understand?

Answer 9

yes i think so

Answer 10

do the x's equal -5 and 2

Answer 11

i put that as the answer but the computer's saying that it's incorrect

Answer 12

that's because you have to check if the answers are possible.
In this case, when you fill in x=-5
You'll get Log10(-5)+Log10(-2)=1

Answer 13

you can't take the Log of a negative number.
So the only right answer is x=2

Answer 14

oh ok that makes so much sense

Answer 15

thank you!