All categories

3 years ago

Examine the work shown. Explain the error and find the correct result.

Mathematics

2 answers:

Vedmedyk [2.9K]3 years ago

6 0

Answer:

The product of two numbers with different signs is negative, so 2(-12) = -24, not 24. Then -24 — (-30) = -24 + 30 = 6.

Step-by-step explanation:

Zepler [3.9K]3 years ago

5 0

2(-12) isn't 24.

It is -24.

So the answer would be 6.

You might be interested in

The angle between a diagonal and the longer base of the isosceles trapezoid MNFD is 45°. NK is an altitude to the longer base. I

Elanso [62]

Answer:

$NK \approx 7.001$ , $MK = 2$ , $MF \approx 7.001$ , $A_{AMNFD} = 49.007$

Step-by-step explanation:

According to the statement, we find the following inputs:

$\angle MDK = \angle DMF = 45^{\circ}$ (Due to the condition of isosceles trapezoid)

$MD = 9$

$NF = 5$

Given than longer base and shorter base are parallel to each other, we conclude that:

$\angle KND = 180^{\circ} -\angle NKD - \angle KDN$

$\angle KND = 180^{\circ}-90^{\circ}-45^{\circ}$

$\angle KND = 45^{\circ}$

$\angle FND = 90^{\circ}-\angle KND$

$\angle FND = 45^{\circ}$ (By definition of complementary angles)

$\angle FND = \angle NFM = 45^{\circ}$ (Due to the condition of isosceles trapezoid)

$\angle MDK = \angle DMF = \angle FND = \angle NFM = 45^{\circ}$

$\angle NOF = \angle MOD = \angle MOF = \angle FOD = 90^{\circ}$ (By definitions of complementary and vertical angles and the theorem that states that sum of internal angles within a triangle equals 180º)

$MO = DO = \frac{\sqrt{2}}{2}\cdot MD$ (By theorem for 45-45-90 Right Triangle)

$NO = OF = \frac{\sqrt{2}}{2}\cdot NF$ (By theorem for 45-45-90 Right Triangle)

If we know that $MD = 9$ and $NF = 5$ , then we find that:

$DO = MO \approx 6.364$

$NO = OF \approx 3.536$

The value of MK is obtained from the following relationship:

$MK = \frac{MD-NF}{2}$

$MK = \frac{9-5}{2}$

$MK = 2$

And the value of KD is calculated from this expression:

$KD = MD-MK$

$KD = 9-2$

$KD = 7$

Now by the Pythagorean Theorem we find that:

$NK = \sqrt{(NO+DO)^{2}-KD^{2}}$

$NK = \sqrt{9.9^{2}-7^{2}}$

$NK \approx 7.001$

And considering the symmetry characteristics of an isosceles trapezoid, we determine MF:

$MF = NO + DO \approx 7.001$

Lastly, the area of the isosceles trapezoid is determined by the following formula:

$A_{AMNFD} = NF\cdot NK + MK\cdot NK$

$A_{AMNFD} = NK\cdot (NF+MK)$

If we know that $NK \approx 7.001$ , $NF = 5$ and $MK = 2$ , then the area of the figure is:

$A_{AMNFD} = (7.001)\cdot (5+2)$

$A_{AMNFD} = 49.007$

8 0

3 years ago

3/1 x 2 /58 what is it

olya-2409 [2.1K]

Answer:

the answer would be 21/5 or 4.5

Step-by-step explanation:

to solve this equation you would use the butterfly method

3/1 x 2/58

3x28=84 and 5x1=5

your fraction is going to be 84/5.

84 can be reduced to 21. so your answer would be 21/5. in the decimal form, it would be 4.5

5 0

2 years ago

look at my the expression below. 1/2 (a+b) - (a-b)2 what is the value of the expression when a= 18 and b =14?

oksano4ka [1.4K]

8 because 18+14 =32 then divide 32 by 2. Then 18-14= 4 then multiply that by 2 and you get 8. 16 -8 = 8

3 0

3 years ago

If f(x)= 2x^2 -4x and g(x) = 5 – 2x, evaluate f(x) – g(x) for x = 5

Orlov [11]

If f(x)= 2x^2 -4x and g(x) = 5 – 2x, evaluate f(x) – g(x) for x = 5

you first plug in 5 for x in both equations...
(2(5)^2-4(5))=f(x)
5-2(5)=g(x)

now you evaluate...
(2(25)-20)-5-10
50-30-15
20-15=5
Answer:
5

6 0

3 years ago

Which is equivalent to log 1/2^462?

AysviL [449]

−8.85174904141 is log 1/2^462

8 1

4 years ago

Read 2 more answers