Ask question

Ask question

All categories

3 years ago

6

One of the equations below is not correct. Which on is incorrect. Then explain the error that was made and write the correct ans

wer.
(-14)(20)=-280
-63divided by -9=7
-6(-2)(3)(-4)(1)=144
-5(-2)(3)(-1)(-7)=210

1 answer:

timurjin [86]3 years ago

3 0

Only 3 is false, because of spare minus.

You might be interested in

Which of the following options have the same value as 30\%30%30, percent of 818181?

Nataly_w [17]

Answer:

Option B is correct = $0.3 \times 81$

Step-by-step explanation:

<u>The complete question is:</u> Which of the following options have the same value as 30% of 81?

Group of choices is:

(A) $\frac{30}{100}\times 81 \times 100$

(B) $0.3 \times 81$

(C) $0.03 \times 81$

(D) $\frac{3}{10}\times 81 \times 10$

(E) $30 \times 81$

Now, the expression given to us is 30% of 81.

Simplifying the above expression we get;

30% of 81 = $\frac{30}{100} \times 81$

= $\frac{3}{10} \times 81$ = $0.3 \times 81$

Now, we will solve each of the given options and then see which option matches with our calculation.

Option (A) is given;

$\frac{30}{100}\times 81 \times 100$ = $30 \times 81$

This doesn't match with our answer, so this option is not correct.

Option (B) is given;

$0.3 \times 81$

<u><em>This matches with our answer, so this option is correct.</em></u>

Option (C) is given;

$0.03 \times 81$

This doesn't match with our answer, so this option is not correct.

Option (D) is given;

$\frac{3}{10}\times 81 \times 10$ = $3 \times 81$

This doesn't match with our answer, so this option is not correct.

Option (E) is given;

$30 \times 81$

This doesn't match with our answer, so this option is not correct.

6 0

3 years ago

Simplest form 2/5ths

ratelena [41]

Answer:

2/5 is the simplest form. But in decimal form it is 0.4

Step-by-step explanation:

2/5

=2 divided by 5

=0.4

7 0

2 years ago

Read 2 more answers

Consider a particle moving along the x-axis where x(t) is the position of the particle at time t, x' (t) is its velocity, and x'

vodka [1.7K]

Answer:

a) $v(t) =x'(t) = \frac{dx}{dt} = 3t^2 -12t +9$

$a(t) = x''(t) = v'(t) =6t-12$

b) $0$

c) $a(t) = x''(t) = v'(t) =6t-12$

When the acceleration is 0 we have:

$6t-12=0, t =2$

And if we replace t=2 in the velocity function we got:

$v(t) = 3(2)^2 -12(2) +9=-3$

Step-by-step explanation:

For this case we have defined the following function for the position of the particle:

$x(t) = t^3 -6t^2 +9t -5 , 0\leq t\leq 10$

Part a

From definition we know that the velocity is the first derivate of the position respect to time and the accelerations is the second derivate of the position respect the time so we have this:

$v(t) =x'(t) = \frac{dx}{dt} = 3t^2 -12t +9$

$a(t) = x''(t) = v'(t) =6t-12$

Part b

For this case we need to analyze the velocity function and where is increasing. The velocity function is given by:

$v(t) = 3t^2 -12t +9$

We can factorize this function as $v(t)= 3 (t^2- 4t +3)=3(t-3)(t-1)$

So from this we can see that we have two values where the function is equal to 0, t=3 and t=1, since our original interval is $0\leq t\leq 10$ we need to analyze the following intervals:

$0< t$

For this case if we select two values let's say 0.25 and 0.5 we see that

$v(0.25) =6.1875, v(0.5)=3.75$

And we see that for $a=0.5 >0.25=b$ we have that f(b)>f(a) so then the function is decreasing on this case.

$1$

We have a minimum at t=2 since at this value w ehave the vertex of the parabola :

$v_x =-\frac{b}{2a}= -\frac{-12}{2*3}= -2$

And at t=-2 v(2) = -3 that represent the minimum for this function, we see that if we select two values let's say 1.5 and 1.75

v(1.75) =-2.8125< -2.25= v(1.5) so then the function sis decreasing on the interval 1<t<2

$2$

We see that the function would be increasing.

$3$

For this interval we will see that for any two points a,b with $a>b$ we have $f(a)>f(b)$ for example let's say a=3 and b =4

$f(a=3) =0 , f(b=4) =9 , f(b)>f(a)$

The particle is moving to the right then the velocity is positive so then the answer for this case is: $0$

Part c

$a(t) = x''(t) = v'(t) =6t-12$

When the acceleration is 0 we have:

$6t-12=0, t =2$

And if we replace t=2 in the velocity function we got:

$v(t) = 3(2)^2 -12(2) +9=-3$

5 0

3 years ago

A group of friends goes out to lunch. The total bill, excluding tax, is $22. If tax on the meal is 6% and if a 20% tip is left o

TiliK225 [7]

Answer:

27.72

Step-by-step explanation:

Sorry about before i made a slight mistake

5 0

1 year ago

A land owner is planning to build a fenced-in, rectangular patio behind his garage, using his garage as one of the "walls." He

Vitek1552 [10]

Answer:

Maximum area = 800 square feet.

Step-by-step explanation:

In the figure attached,

Rectangle is showing width = x ft and the side towards garage is not to be fenced.

Length of the fence has been given as 80 ft.

Therefore, length of the fence = Sum of all three sides of the rectangle to be fenced

80 = x + x + y

80 = 2x + y

y = (80 - 2x)

Now area of the rectangle A = xy

Or function that represents the area of the rectangle is,

A(x) = x(80 - 2x)

A(x) = 80x - 2x²

To find the maximum area we will take the derivative of the function with respect to x and equate it to zero.

$A'(x)=\frac{d}{dx}(80x-2x^{2})$

= 80 - 4x

A'(x) = 80 - 4x = 0

4x = 80

x = $\frac{80}{4}$

x = 20

Therefore, for x = 20 ft area of the rectangular patio will be maximum.

A(20) = 80×(20) - 2×(20)²

= 1600 - 800

= 800 square feet

Maximum area of the patio is 800 square feet.

7 0

3 years ago