Answer:
x = -1/2
Step-by-step explanation:
This question can be solved by applying the laws of indices
In a^n, a - base
n - index
Given
9^x = 1/3
According to the laws of indices, a/b = b^(-a)
Hence we can write, 1/3 = 3^(-1)
9^x = 3^(2x)
Again according to the laws of indices,
a^b = a^n can be written as;
b = n
That is, if in an equation the bases are the same, the indices are also equal.
So we can write,
3^(2x) = 3^(-1)
2x = -1
Divide both sides of the equation by 2, the coefficient of x
2x/2 = -1/2
x = -1/2
I actually posted this a while ago and it got answerd by a smart person so here's what I understood
the error is that it assumes that √(x²)=x
because if x is negative, it becomes positive
that's how the 2nd line is wrong
the 2nd line is the first wrong step
it goes from 4-9/2+9/2
so it goes from 4-4.5+4.5
notice the part under the parenthsees
√((4-4.5)²)
if we evaluate 4-4.5, we get -0.5
but by squaring it we get 0.5
-0.5+4.5=4, yes
but when we square it we get
0.5+4.5=5, that is how it works
The answer is -7 because when you minus a negative number you add it, and -10 + 3 is -7. I hope this helps!
Let's write some equations.
Mingwei's distance from Town A after
hours from 8:00 is
.
Ali's distance from Town B after
hours is
, since he doesn't start walking for 40 minutes.
When Mingwei's distance is twice Ali's, they've met up (since their distance from Town A is twice their distance from Town B).
So, this gives
, so
, so
, so the time is 10:40.
After
hours, Mingwei has traveled
kilometers while Ali has traveled sixty, so the distance between the towns is
kilometers.
Answer:
El reloj de Nuestra Basílica de Chiquinquirá empleará 20 segundos para indicar las 8 a.m.
Step-by-step explanation:
De acuerdo a la información proporcionada, sabes que el reloj de Nuestra Basílica de Chiquinquirá señala cada hora con igual número de campanadas, por lo que a las 8 a.m. tocará 8 campanadas y puedes usar una regla de tres para encontrar cuantos segundos empleará en hacerlo dado que conoces que las 6 campanadas se demoran 15 segundos:
6 campanadas → 15 segundos
8 campanadas → x
x=(8*15)/6
x= 20
De acuerdo a esto, la respuesta es que el reloj de Nuestra Basílica de Chiquinquirá empleará 20 segundos para indicar las 8 a.m.
