X=one type that cost 9
y=one type that cost 8
total books=type1+type2
total books=13
x+y=13
the total cost=cost of each added together
cost of each=number of books times cost per book
total cost=108
9x+8y=108
we have
x+y=13
9x+8y=108
solve for x and y
multiply first equation by -8 and add to first equation
-8x-8y=-104
<u>9x+8y=108 +</u>
x+0y=4
x=4
subsitute
x+y=13
4+y=13
minus 4
y=9
4 of the $9
9 of the $8
thats how to solve
Answer:
DE = 20 units
Step-by-step explanation:
<u><em>GIVEN</em></u><em> :-</em>
- D & E are the mid-points of AB & BC respectively.
- DE = 4x + 4
- AC = x + 36
<u><em>TO FIND</em></u><em> :-</em>
<u><em>FACTS TO KNOW BEFORE SOLVING</em></u><em> :-</em>
- The midsegment of a triangle is a line constructed by connecting the midpoints of any two sides of the triangle.
- The Triangle Midsegment Theorem tells us that a midsegment is one-half the length of the third side (the base), and it is also parallel to the base.
<u><em>PROCEDURE</em></u><em> :-</em>
According to Triangle Midsegment Theorem ,
![DE = \frac{AC}{2}](https://tex.z-dn.net/?f=DE%20%3D%20%5Cfrac%7BAC%7D%7B2%7D)
![=> 4x + 4 = \frac{x + 36}{2}](https://tex.z-dn.net/?f=%3D%3E%204x%20%2B%204%20%3D%20%5Cfrac%7Bx%20%2B%2036%7D%7B2%7D)
Multiplying 2 on both the sides ,
![=> 2(4x + 4) = x + 36](https://tex.z-dn.net/?f=%3D%3E%202%284x%20%2B%204%29%20%3D%20x%20%2B%2036)
![=> 8x + 8 = x + 36](https://tex.z-dn.net/?f=%3D%3E%208x%20%2B%208%20%3D%20x%20%2B%2036)
![=> 8x - x = 36 - 8](https://tex.z-dn.net/?f=%3D%3E%208x%20-%20x%20%3D%2036%20-%208)
![=> 7x = 28](https://tex.z-dn.net/?f=%3D%3E%207x%20%3D%2028)
![=> x = \frac{28}{7} = 4](https://tex.z-dn.net/?f=%3D%3E%20x%20%3D%20%5Cfrac%7B28%7D%7B7%7D%20%3D%204)
∴ DE = 4×4 + 4 = 20 units
9514 1404 393
Answer:
cm to m
Step-by-step explanation:
There are 100 centimeters in a meter, so one possibility is conversion of a length measurement from centimeters to meters.
Answer:
£17.59
Step-by-step explanation:
100 + 10 = 110% (Price of a ticket after increase)
110% = 19.35
1% = 19.35 ÷ 110 = 0.1759
100% = 0.1759 x 100 = 17.59