Answer:
If a certain cone with a height of 9 inches has volume V = 3πx2 + 42πx + 147π, what is the cone’s radius r in terms of x?
Step-by-step explanation:
V = 3πx2 + 42πx + 147π
V=3π(x2 + 14x +49)
9.42(x2 + 14x +49)
9.42(x2 + 14x +14) -14 + 49= 0
9.42(x + 7)^2 + 35= 0
9.42(9.42(x + 7)^2 = - 35)9.42
(x + 7)^2 = - 35/9.42)
√(x + 7)^2=√- 35/9.42
x + 7 = - 1.927
x= - 1.927 - 7
x= - 8.927
V = 3π(- 8.927)^2 + 42π(- 8.927) + 147π
V=750.69 - 1177.29 + 461.58
<u>V=34.98</u>
h= 9 inches
V = 13πr2h
34.98 = 13(3.14) (r^2) (h)
34.98 = 40.82 (r^2) 9
34.98 = 367.38 r^2
34.98/ 367.38 = 367.38 r^2/ 367.38
0.095= r^2
Answer:
Step-by-step explanation:
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3) x² - 121 = 0
x² = 121
x' = +√121
x' = 11
_______________
x'' = - √121
x'' = -11
Solution ⇒ S{-11 ; 11 } or (x-11)(x+11)
4) 4x² + 144 = 0
4x² = -144
x² = -144 / 4
x² = -36
x = √-36
No solution ⇒ S = ∅
5) z²+10z+21 = 0
Δ = 10² - 4(1)(21)
Δ = 100 - 84
Δ = 16
x' = (-10+4) / 2 = -6/2 = -3
x'' = (-10-4) / 2 = -14/2 = -7
Solution ⇒ S{ -7 ; -3} or (x+3)(x+7)
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Answer:
cups of flour
Step-by-step explanation:
A muffin recipe, which yields 12 muffins, calls for 2/3 cup of milk for every 1 3/4 cups of flour.
Then this recipe, which yields one muffin, calls for

cup of milk for every

cups of flour.
Thus,
this recipe, which yields a batch of 30 muffins, calls for

cups of milk for every

cups of flour.