Answer:
19 red beads
Step-by-step explanation:
We first need to find a common denominator of 4/9, 1/5 and 1/4.
The common denominator is 180. Like in an expression, what we do to one side we have to do to the other.
Silver - 180/9 = 20 ; 20*4 = 80 so there are roughly 80 sliver beads.
Gold - 180/5 = 36 ; 36*1 = 36 so there are roughly 36 gold beads.
Blue - 180/4 = 45 ; 45*1 = 45 so there are roughly 56 blue beads.
180 - (silver+gold+blue) = red beads
180-161 = 19 red beads b/c ----->
80+36+45+19 = 180
First, let us restate the given conditions
c is 5 more than variable a ( c = a + 5)
c is also three less than variable a (c = a - 3)
Now, lets look at the answer choices and or given
c = a − 5
c = a + 3
Here, c is 5 less than "a"...so automatically disqualified
a = c + 5
a = 3c − 3
Here, we have to get "C" by itself in both top and bottom equation.
So,
Simplified version :
c = a - 5
Here, c is 5 less than "a"...so automatically disqualified
a = c − 5
a = 3c + 3
Here also, we have to get "C" by itself in both top and bottom equation.
So,
simplified version:
c = a + 5
Here, c is 5 more than "a"...so we continue
c = (a - 3) / 3
Here, c is 3 less than "a" <u>divided by 3</u><u /> . So, this is not correct
c = a + 5
c = a − 3
Here, c is 5 more than "A"
Also, c is 3 less than "a"
Which satisfies the given.
So, our answer is going to be the last one:
c = a + 5
c = a - 3
Let x=ab=ac, and y=bc, and z=ad.
Since the perimeter of the triangle abc is 36, you have:
Perimeter of abc = 36
ab + ac + bc = 36
x + x + y = 36
(eq. 1) 2x + y = 36
The triangle is isosceles (it has two sides with equal length: ab and ac). The line perpendicular to the third side (bc) from the opposite vertex (a), divides that third side into two equal halves: the point d is the middle point of bc. This is a property of isosceles triangles, which is easily shown by similarity.
Hence, we have that bd = dc = bc/2 = y/2 (remember we called bc = y).
The perimeter of the triangle abd is 30:
Permiter of abd = 30
ab + bd + ad = 30
x + y/2 + z =30
(eq. 2) 2x + y + 2z = 60
So, we have two equations on x, y and z:
(eq.1) 2x + y = 36
(eq.2) 2x + y + 2z = 60
Substitute 2x + y by 36 from (eq.1) in (eq.2):
(eq.2') 36 + 2z = 60
And solve for z:
36 + 2z = 60 => 2z = 60 - 36 => 2z = 24 => z = 12
The measure of ad is 12.
If you prefer a less algebraic reasoning:
- The perimeter of abd is half the perimeter of abc plus the length of ad (since you have "cut" the triangle abc in two halves to obtain the triangle abd).
- Then, ad is the difference between the perimeter of abd and half the perimeter of abc:
ad = 30 - (36/2) = 30 - 18 = 12
It is B identity property of division. Because you are dividing by one and that is a part of what the identity property of division.
