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3 years ago

What is one value of x that makes the equation-16x^2+121=0 true

Mathematics

1 answer:

jeyben [28]3 years ago

8 0

Answer:

x = ±11/4

Step-by-step explanation:

Rewrite -16x^2+121=0 as 16x^2 - 121=0 and then as 16x^2 = 121.

Take the square root of both sides. This returns 4x = ±11, and so:

x = ±11/4

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6+8(y-3/5), if y=8/9

skad [1K]

374/45 is the answer

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2 years ago

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Use the exponential decay model, Upper A equals Upper A 0 e Superscript kt, to solve the following. The half-life of a certai

Akimi4 [234]

Answer:

It will take 7 years ( approx )

Step-by-step explanation:

Given equation that shows the amount of the substance after t years,

$A=A_0 e^{kt}$

Where,

$A_0$ = Initial amount of the substance,

If the half life of the substance is 19 years,

Then if t = 19, amount of the substance = $\frac{A_0}{2}$ ,

i.e.

$\frac{A_0}{2}=A_0 e^{19k}$

$\frac{1}{2} = e^{19k}$

$0.5 = e^{19k}$

Taking ln both sides,

$\ln(0.5) = \ln(e^{19k})$

$\ln(0.5) = 19k$

$\implies k = \frac{\ln(0.5)}{19}\approx -0.03648$

Now, if the substance to decay to 78% of its original amount,

Then $A=78\% \text{ of }A_0 =\frac{78A_0}{100}=0.78 A_0$

$0.78 A_0=A_0 e^{-0.03648t}$

$0.78 = e^{-0.03648t}$

Again taking ln both sides,

$\ln(0.78) = -0.03648t$

$-0.24846=-0.03648t$

$\implies t = \frac{0.24846}{0.03648}=6.81085\approx 7$

Hence, approximately the substance would be 78% of its initial value after 7 years.

5 0

3 years ago

Simplify. please7−5x−(3+5x) 4 + 10x44−10x10 + 10x

Alenkasestr [34]

Simplify the expression:

7 - 5x - (3 + 5x)

Operate the parentheses. Each term changes its signs because the minus sign represents a -1:

7 - 5x - (3 + 5x) = 7 - 5x - 3 - 5x

Collect like terms:

7 - 5x - (3 + 5x) = 7 - 3 -5x - 5x

Simplify:

7 - 5x - (3 + 5x) = 4 - 10x

Answer: 4 - 10x

8 0

1 year ago

What is the solution to this equation -13x=52

Tom [10]

Answer:

-4

Step-by-step explanation:

You multiply -13*-4=52

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3 years ago

What is the exponent of 20

Ilia_Sergeevich [38]

I think it is 0 because I googled it.

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3 years ago

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