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2 years ago

11

100 POINTS!! somebody please answer! but it has to correct!

1 answer:

slava [35]2 years ago

6 0

Step-by-step explanation:

$\left\{\begin{array}{ccc}x-7y=4&\text{multiply both sides by 3}\\-3x+21y=5\end{array}\right\\\underline{+\left\{\begin{array}{ccc}3x-21y=12\\-3x+21y=5\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad\qquad0=17\qquad\bold{FALSE}\\\\\bold{CONCLUSION:}\ \bold{no\ solutions}\\\\\text{What do you know about the two lines in the system of equations? }\\\\\text{The lines do not have a common point (s).}\\\text{They don't intersect. Therefore, they are parallel lines.}$

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Evaluate log416 -2 1/2 2

krok68 [10]

16 = 4²

So, by the definition of logarithms

$\log_4{16}=2$

5 0

2 years ago

Algebra Expression •x minus x

Tems11 [23]

The answer is 0.

The expression in algebraic form is :

x - x
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4 0

1 year ago

Read 2 more answers

If the local linear approximation of f(x) = 2cos x + e^2x at x = 2 is used to find the approximation for f(2.1), then the % erro

yKpoI14uk [10]

<u>Answer-</u>

The % error of this approximation is 1.64%

<u>Solution-</u>

Here,

$\Rightarrow f(x) = 2\cos x + e^{2x}$

$\Rightarrow f'(x) = -2\sin x + 2e^{2x}$

And,

$\Rightarrow f(2) = 2\cos 2 + e^{4}$

$\Rightarrow f'(2) = -2\sin 2 + 2e^{4}$

Taking (2, f(2)) as a point and slope as, f'(2), the function would be,

$\Rightarrow y-y_1=m(x-x_1)$

$\Rightarrow y-(2\cos 2 + e^{4})=(-2\sin 2 + 2e^{4})(x-2)$

$\Rightarrow y=(-2\sin 2 + 2e^{4})(x-2)+(2\cos 2 + e^{4})$

The value of f(2.1) will be

$\Rightarrow y=(-2\sin 2 + 2e^{4})(2.1-2)+(2\cos 2 + e^{4})$

$\Rightarrow y=(-2\sin 2 + 2e^{4})(0.1)+(2\cos 2 + e^{4})$

$\Rightarrow y=64.5946$

According to given function, f(2.1) will be,

$\Rightarrow f(2.1) = 2\cos 2.1 + e^{2(2.1)}$

$\Rightarrow f(2.1) = 65.6766$

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5 0

2 years ago

A survey of Mr. Thorne’s class shows that 5 out of 8 students will buy lunch today. Based on this result, how many of the 720 st

Ipatiy [6.2K]

450

5:8.
X:720

8x90=720 so multiply 5x90

450

7 0

2 years ago

A person invest $1200 in an account that earns 2% interest compound quarterly. Find when the value of the investment reaches $15

Basile [38]

Answer:

After 11 years the value of the investment reaches $1500.00

.

Step-by-step explanation:

The formula used for finding time (when the value reaches certain amount) is:

$A= P(1+\frac{r}{n})^{nt}$

where A= Future VAlue

P= Principal Value

r= rate of interest (in decimal)

n= no of times investment is compounded

t= time

Putting the values given and finding Time t,

A= $1500

P= $1200

r= 2% or 0.02

n= 4 (compound quarterly)

$A= P(1+\frac{r}{n})^{nt}$

$1500= 1200(1+\frac{0.02}{4})^{4t}$

Dividing both sides by 1200 and solving 0.02/4 = 0.005

$1.25= (1+0.005)^{4t}$

$1.25= (1.005)^{4t}$

Since t is in power we take the logarithm ln on both sides.

The rule of logarithm says that the exponent can be multiplied with the base when taking log

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8 0

2 years ago