All categories

3 years ago

1 2/7 divided by (-2 1/4)

Mathematics

2 answers:

Oliga [24]3 years ago

5 0

Hey there! :)

Answer:

-4/7.

Step-by-step explanation:

Convert 1 2/7 to an improper fraction:

1 2/7 --> $\frac{9}{7}$

Convert -2 1/4 to an improper fraction:

-2 1/4 --> $\frac{-9}{4}$

Divide by multiplying by the reciprocal:

$\frac{9}{7} * \frac{4}{-9}= \frac{9*4}{7*(-9)}= \frac{-4}{7}$

Therefore, 1 2/7 divided by -2 1/4 equals -4/7.

zubka84 [21]3 years ago

5 0

1 2/7=9/7
-2 1/4=-9/4
(9/7)/(-9/4)=36/-63
=-4/7

You might be interested in

In a scale model of a roller coaster, the highest hill has a height of 6 inches. If the actual height of the hill is 210 feet, w

klio [65]

That would be 1 inch = 35 feet

5 0

4 years ago

Read 2 more answers

If the following figure was reflected across the x-axis, what would be the coordinates of D'?

Free_Kalibri [48]

Answer: 5, -4

Step-by-step explanation:

imagine a mirror on the x axis and just make it look symmetrical and that will help you. Its also the complete opposite of the point

4 0

3 years ago

4. IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. In a

borishaifa [10]

675 people will have score between 85 and 120

Step-by-step explanation:

Given

Mean = 100

SD = 15

If we have to find percentage of score between two values we have to find the z-score for both values and then area under the curve for both values

z-score is given by:

for a value x:

$z-score = \frac{x-mean}{SD}$

So,

For 85:

$z-score = z_1 = \frac{85-mean}{SD}\\ = \frac{85-100}{15}\\=\frac{-15}{15}\\=-1$

$z-score = z_2 = \frac{120-mean}{SD}\\ = \frac{120-100}{15}\\=\frac{20}{15}\\=1.3333$

Now we have to find the area under the curve for both values of z-score. z-score tables are used for this purpose.

So,

For z1 : 0.1587

For z2: 0.9082

The area between z11 and z2:

$z_2-z_1 = 0.9082-0.1587=0.7495$

So the probability of score between 85 and 120 is 0.7495

As the sample is of 900 people, the people with scores between 85 and 120 will be:

900*0.7495 = 674.55 people

Rounding off to nearest whole number

675 people will have score between 85 and 120

Keywords: Probability, SD

Learn more about probability at:

#LearnwithBrainly

4 0

4 years ago

in the given figure, AB//PQ//CD. AB = x units. CD = y units and PQ = z unites. Prove that 1/x + 1/y = 1/z

Arlecino [84]

12. ∆ABD is similar to ∆PQD, so
QD/z = BD/x
Likewise ∆CDB is similar to ∆PQB, so
QB/z = BD/y

Since QD + QB = BD, you have
QD/z + QB/z = BD/x + BD/y
BD/z = BD/x + BD/y
Dividing by BD gives the desired result:
1/x + 1/y = 1/z

13. Triangles ABD, BCD, and ACB are all similar. This means
AB/AC = AD/AB
AB² = AC×AD = (4 cm)×(9 cm)
AB² = 36 cm²
AB = 6 cm
and
BD/CD = AD/BD
BD² = CD×AD = (5 cm)×(4 cm)
BD² = 20 cm²
BD = 2√5 cm

7 0

3 years ago

A group of 18 people ordered soup and sandwiches for lunch. Each person in the group had either one soup or one sandwich. The sa

Black_prince [1.1K]

X - the number of sandwiches
y - the number of soups

$x+y=18 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ |\times (-4.5) \\
7.75x+4.5y=113.5 \\ \\
-4.5x-4.5y=-81 \\
\underline{7.75x+4.5y=113.5} \\
7.75x-4.5x=113.5-81 \\
3.25x=32.5 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ |\div 3.25 \\
x=10$

10 sandwiches were ordered. The answer is D.

6 0

3 years ago

Read 2 more answers