Answer:

Step-by-step explanation:
<u>System of Equations</u>
Let's call:
x = number of nickels in the student's pocket
y = number of dimes in the student's pocket
Each nickel has a value of $0.05, so x nickels have a value of 0.05x
Each dime has a value of $0.10, so y dimes have a value of 0.10y
The student has a total of 10 coins, thus:

The total value of the coins is $0.85, thus

The system of linear equations that represents this scenario is:

You can solve this by putting the number of copies in the top part of the fraction. If you replace the one in the top part of 1/6 with 3, you get the fraction 3/6. Half of six is three and half of two is one, so both fractions are equal. You can test this be dividing the 3 in the top by 3 and the 6 in the bottom by three. Your result will be 1/2. Although there are three times ad many copies, each copy is three times as small, so it balances out.
Triangle ABC is an isosceles triangle.
Solution:
Given data:
∠ABC = 70° and ∠ACD = 55°
<em>If two parallel lines are cut by a transversal, then alternate interior angles are congruent.</em>
m∠BAC = m∠ACD
m∠BAC = 55°
<em>Sum of the angles in a straight line add up to 180°.</em>
m∠ACD + m∠ACB + m∠ABC = 180°
55° + m∠ACB + 70° = 180°
m∠ACB + 125° = 180°
Subtract 125° from both sides, we get
m∠ACB = 55°
In triangle ABC,
∠BAC = 55° and ∠ACB = 55°
∠BAC = ∠ACB
Two angles in the triangle are equal.
Therefor triangle ABC is an isosceles triangle.
Answer:
12/13
Step-by-step explanation:
We know that cosine is the adjacent side divided by the hypotenuse in a right triangle.
The adjacent side to angle C is BC
The hypotenuse is AC because it is opposite to the right angle
So...
cosine is (BC)/(AC)
36/39
12/13