Please Help Find the area of a circle with radius,
r
= 87cm.
Give your answer rounded to 3 SF.

Step-by-step explanation:

so, to repeat, the radius r of the circle is 87 cm.

the area of a circle is

pi×r²

so, in our case

A = pi×87² = pi×7569 = 23,778.7148... cm²

so, how to give this answer with only 3 significant figures ?

as you can see, there are already 5 figures before the decimal point.

3 attempts :

1. 3 significant figures after the decimal point : 23778.715 cm²

2. scientific notation with 3 SF : 2.38×10⁴ cm²

3. converting to m² (1m² = 10000cm²) : 2.38 m²

30 people weigh 160 pounds or more

simplifying

5(x + -6) = 2(x + 3)

reorder the terms:

5(-6 + x) = 2(x + 3)

(-6 * 5 + x * 5) = 2(x + 3)

(-30 + 5x) = 2(x + 3)

reorder the terms:

-30 + 5x = 2(3 + x)

-30 + 5x = (3 * 2 + x * 2)

-30 + 5x = (6 + 2x)

solving

-30 + 5x = 6 + 2x

solving for variable 'x'.

move all terms containing x to the left, all other terms to the right.

add '-2x' to each side of the equation.

-30 + 5x + -2x = 6 + 2x + -2x

combine like terms: 5x + -2x = 3x

-30 + 3x = 6 + 2x + -2x

combine like terms: 2x + -2x = 0

-30 + 3x = 6 + 0

-30 + 3x = 6

add '30' to each side of the equation.

-30 + 30 + 3x = 6 + 30

combine like terms: -30 + 30 = 0

0 + 3x = 6 + 30

3x = 6 + 30

combine like terms: 6 + 30 = 36

3x = 36

divide each side by '3'.

x = 12

simplifying

x = 12

this should .