Circumference = 2 $\pi$ r
   42 = 2 $\pi$ r
42/(2 $\pi$ ) = r
21/ $\pi$ = r

Area = $\pi$ r²
   = $\pi$ (21/ $\pi$ )²
   = 21²/ $\pi$
   = 140.37
   ≈ 140.4

Answer: A

7 0

3 years ago

3x+2y=10<br> 12x+5y=25<br><br> Solve by substitution or elimination

zaharov [31]

3x + 2y = 10 ....multiply by -4
12x + 5y = 25
-------------------
-12x - 8y = -40 (result of multiplying by -4)
12x + 5y = 25
------------------add
-3y = - 15
y = -15/-3
y = 5

3x + 2y = 10
3x + 2(5) = 10
3x + 10 = 10
3x = 10 - 10
3x = 0
x = 0

solution is (0,5)

5 0

3 years ago

I really need help:(​

I really need help:(