6x - 15 = 90
6x = 90 + 15
6x = 105
x = 105/6
x = 17.5
Answer:
C. 42
Step-by-step explanation:
<em>Since the triangle making up the base of the right triangular pyramid is equilateral, the three lateral triangles will have equal areas. To find the surface area of the pyramid, find the area of one of the lateral triangles and multiply it by 3. Then, add that to the area of the triangle that forms the base.</em>
<em>Area of Lateral Triangle = 1/2 · base · height</em>
<em> = 1/2 · X · Z</em>
<em> = 1/2 · 4 units · 6 units</em>
<em> = 12 square units</em>
<em>Area of Base Triangle = 1/2 · base · height</em>
<em> = 1/2 · X · Y</em>
<em> = 1/2 · 4 units · 3 units</em>
<em> = 6 square units</em>
<em>Now, use the method described above to find the surface area of the pyramid.</em>
<em>Surface Area = 3( Area lateral ) + ( Area base )</em>
<em> = 3 ( 12 square units ) + ( 6 square units )</em>
<em> = 42 square units</em>
Given - Dimensions of brick - 30cm ×10cm ×7 1/2 cm
Dimensions of wall - 30cm long 2m high and 3/4m thick
Find - Number of bricks
Solution - The volume of both brick and wall will be calculated by the formula Length*breadth*height.
Volume of one brick = 30*10*15/2
Volume of one brick = 30*10*7.5
Volume of one brick = 2250 cm³
Now calculating volume of wall. Firstly converting height and thickness into centimetres.
Height = 2 metres
Height = 200 centimetres.
Thickness = 3/4 metres
Thickness = 75 centimetres
Volume of wall = 30*75*200
Volume of wall = 4,50,000 cm³
Number of bricks required = 450000/2250
Number of bricks required = 200
Thus, 200 bricks will be required for given wall.
Answer:
[-2,-3]
Step-by-step explanation:
In component vertex form: [-2,-3]