Answer:
i think a is the right answer
Answer:
20 children.
Step-by-step explanation:
We can solve this using an equation or simple mental math:
The equation: x=children x+20=adults
x + (x+20) = 60
2x + 20 = 60
2x = 40
x = 20
Mental Math: 40 plus 20 is 60 and 40 is 20 more than 20 so there are 40 adults and 20 children.
Answer:
43.8 is the Area but i don't know about the perimeter
Step-by-step explanation:
Answer:
Step-by-step explanation:
1. Use of lubricants
Lubricants like oil and grease helps to decrease friction by forming a thin film in between different parts of the machine. This film covers up the scratches and bumps on the surfaces of different parts. This reduces interlocking between the two surfaces. Thus reducing the friction.
2. Use ball bearings
Two moving surfaces in a machine are attached by placing small steel balls or steel rollers in between them. This way, the moving parts avoid direct contact and the force of sliding friction turns into rolling friction. Rolling friction is less than sliding friction, in doing so reducing the friction.
3. Polishing
Polishing reduces the unevenness of a surface. This will reduce interlocking between the surfaces.
4. Streamlining
Streamlining is the process where you make a machine in a shape that avoids air and water resistance. This reduces friction because a streamlined object cuts through the water and air molecules.
The coefficient of this expression is 5, a coefficient is just the number before a variable.
