Let
be the length of the leg with one tick mark and
the length of the leg with two tick marks.
In the upper triangle, the law of cosines says

In the lower triangle, it says

Subtract the second equation from the first to eliminate
:


and
are lengths so they must both be positive. 10 is also positive, so in order to preserve the sign on both sides of this equation, we must have


Now we have to be a bit careful. If
is an acute angle, then as
gets larger, the value of
gets smaller. So if we have two angles
and
, with
, then we would have
.
This means in our inequality, taking the inverse cosine of both sides would reverse the inequality:

We know that
is an angle in a triangle, so it must be some positive measure:

So we must have

2 plants in a square foot
6 plants in a square yard
8 seeds per square foot
Answer:
2 groups
Step-by-step explanation:
- 18 ÷ 9 = 2 groups
I hope this helps!
The values of x, y, and z are 1, 2, and 3 respectively after using the substitution method.
<h3>What is a linear equation?</h3>
It is defined as the relation between two variables, if we plot the graph of the linear equation we will get a straight line.
If in the linear equation, one variable is present, then the equation is known as the linear equation in one variable.
We have a linear equation in three variable:
2x + 3y - z = 5 ...(1)
4x - y - z = -1 ...(2)
x + 4y + z = 12 ...(3)
(from the equation 1 and 2)
After solving:

From the above, two equations:
y =2
z =3
Plug the above values in equation 1
x = 1
Thus, the values of x, y, and z are 1, 2, and 3 respectively after using the substitution method.
Learn more about the linear equation here:
brainly.com/question/11897796
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Answer:
I think b) is the answer I solve it but