Sqrt(1-3x)=x+3
[sqrt(1-3x)]^2=(x+3)^2
1-3x=(x+3)(x+3)
1-3x=x^2+6x+9
-3x=x^2+6x+8
0=x^2+9x+8
The answers are -1 and -8 BUT, we have to plug them back into the original equation to make sure we don't get a negative under the square root sign.
After doing this, we realize that only -1 works, so the answer is x=-1
Sorry that this took forever to answer. I was thinking of a good way to explain this, and if you need any further explanation, message me:)
Best wishes:)
For this case, the first thing to do is to observe that the figure is symmetrical with respect to the FH axis.
Therefore, the following lengths are the same:
So, by equalizing both sides we have:
From here, we clear the value of m.
We have then:
Answer:
The value of m is given by:
You first convert the 2 minutes and 30 seconds to 150 seconds.
Then, you take the 150s÷5m to get the number of seconds per mile.
The answer is 30s/m
The answer and working are shown in the photo below
