Simplify the expression: 7r–3r+9r
1 answer:
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Answer:
The radius is 5 cm
Step-by-step explanation:
The formula for the area of a circle is :
To work out the length of the radius you would first need to divide the area of 78.5 cm by pi (pi=3.14), this gives you . This is because by dividing the area by pi we are isolating the value of the radius squared.
The final step is to work out the radius. You can do this by finding the square root of the radius squared which is 25, this gives you 5 cm. This means that the radius is 5 cm. This is because the square root is a number that when squared equals that number.
1) Divide 78.5 by pi.
2) Find the square root of 25 cm squared.
In this question pi is 3.14