All categories

3 years ago

Given that x2 - y2 = 135 and x - y = 15 , find the value of (x+y)2

Mathematics

1 answer:

kirill [66]3 years ago

6 0

Answer:

x² - y² = 135

<=> (x - y)(x + y) = 135

<=> 15(x + y) = 135

=> x + y = 135/15 = 9

=> (x + y)² = 81

You might be interested in

Which number line shows the solutions to x < 1?

Dimas [21]

Answer:

Step-by-step explanation:

the graph of 'x < 1' must have an open circle on the number 1 with shading to the left (to indicate all values less than one)

5 0

2 years ago

A sample of blood pressure measurements is taken for a group of adults, and those values (mm Hg) are listed below. The values

nika2105 [10]

Answer:

For systolic pressure data:

$\bar X =127.2\\\\S=17.91668\\\\CV=\frac{17.91668}{127.2}=0.14085$

For diastolic pressure data:

$\bar X =73.5\\\\S=12.54\\\\CV=\frac{73.5}{12.54}=0.17061$

Systolic pressure is slightly less variable, among individuals in the sample, than diastolic pressure.

Step-by-step explanation:

The coefficient of variation is defined as the percentage relative variation of a set of data with respect to its average. And it is calculated like this:

$CV=\frac{\bar X}{S}$

$S =\sqrt{\frac{1}{n-1} \sum_{i=1}^n (x_i-\bar{x})^2$

$\bar X={\frac{1}{n} \sum_{i=1}^n x_i$

For systolic pressure data:

$\bar X =127.2\\\\S=17.91668\\\\CV=\frac{17.91668}{127.2}=0.14085$

For diastolic pressure data:

$\bar X =73.5\\\\S=12.54\\\\CV=\frac{12.54}{73.5}=0.17061$

It is observed that the systolic pressure shows greater standard deviation but less coefficient of variation. This is due to the greater magnitude of its measurement scale.

Systolic pressure is slightly less variable, among individuals in the sample, than diastolic pressure.

7 0

3 years ago

There are 100 runners entered in a marathon. How many different groups of three runners can finish in first, second, and third?

Lelu [443]

Any one of the runners could be 1st.
Every runner except for the one that was 1st could be 2nd.
Every runner that wasn't 1st or 2nd could be 3rd.

100*99*98=970200 groups.
This involves permutations because order does matter.

Hope this helps!

3 0

4 years ago

Eighteen boys joined a group of p students in the auditorium. If the ratio of boys to girls was then 5:4 write and algebraic exp

ycow [4]

Answer: The number of girls in the auditorium is represented by the algebraic expression y=(4x +72) /5

Step-by-step explanation:

Hi, to answer this question we have to analyze the information given:

<em>Number of boys added: 18 </em>
<em>Ratio of boys to girls: 5:4 </em>

So, the total number of boys is:

x + 18

Number of girls = y

Number of boys / number of girls = 5/4

(x+18) /y = 5/4

Solving for "y"

4 (x +18) =5 y

4x +72 = 5y

(4x +72) /5 = y

The number of girls in the auditorium is represented by the algebraic expression y=(4x +72) /5

8 0

3 years ago

How to solve 18-4t/.5=20

Damm [24]

Divide .5 4 then do the rest

7 0

3 years ago