Which of the following is the solution to the quadratic equation x2−10x+21=0 ?
2 answers:
You might be interested in
Answer:
About 158 times
Step-by-step explanation:
Represent the rate of human heart with H and sparrow's heart with S
Required
Determine how many times faster is S than H
To do this, we simply divide S by H i.e.
--- approximated
<em>Hence, the sparrow's heart beats about 158 times faster than the human hearts</em>
Our goal here is to somehow "surgically remove" the repeating part of the number, so let's start by putting the original value in a variable and messing around with it a bit.
We'll let . We want to cut the
bit off completely, so let's create the scalpel that'll let us do that. If
, then we can also say that
. Maybe I was lying a bit: the
is our real scalpel here, and
is where we'll be making the cut. Mathematically, a "cut" is almost always shorthand for subtraction, so let's see what our operation (cutting
off of
) leaves us with:
The operation was a success! We can now simply divide either side by 9 to find , which, when reduced by dividing the numerator and denominator by 3, gives us