What is the midpoint of AB?

Length of a rectangle is 5 cm longer than the width. Four squares are constructed outside the rectangle such that each of the sq

TiliK225 [7]

Answer:

The perimeter of rectangle is $18\ cm$

Step-by-step explanation:

Let

x-----> the length of the rectangle

y----> the width of the rectangle

we know that

$x=y+5$ ----> equation A

$120=xy+2x^{2}+2y^{2}$ ---> equation B (area of the constructed figure)

substitute the equation A in equation B

$120=(y+5)y+2(y+5)^{2}+2y^{2}$

$120=(y+5)y+2(y+5)^{2}+2y^{2}\\ 120=y^{2}+5y+2(y^{2}+10y+25)+2y^{2}\\ 120=y^{2}+5y+2y^{2}+20y+50+2y^{2}\\120=5y^{2}+25y+50\\5y^{2}+25y-70=0$

using a graphing calculator -----> solve the quadratic equation

The solution is

$y=2\ cm$

Find the value of x

$x=y+5 ----> x=2+5=7\ cm$

Find the perimeter of rectangle

$P=2(x+y)=2(7+2)=18\ cm$

4 0

3 years ago

Read 2 more answers

PLEASE HELP!!!!!!!!!!!!1

skelet666 [1.2K]

A. Let x = cheese and
y = chocolate
2x + y = 25
x + y = 20

B. Subtract the second equation from the first.
2x + y = 25
-(x + y = 20)
-—————
x = 5

Plug 5 back in to the second equation and solve for y.
x + y = 20
5 + y = 20
Subtract 5 from both sides.
y = 15
5 cheese and 15 chocolate

Used elimination method because coefficients on the y values were both 1 so it was easy to subtract the equations and eliminate the y variable.

5 0

3 years ago

2x² - 5x+1 has roots alpha and beta. Find alpha⁴+beta⁴ without solving the equation.

shepuryov [24]

Answer:

Step-by-step explanation:

$\alpha+\beta=\dfrac{5}{2} \\\\\alpha*\beta=\dfrac{1}{2} \\\\\alpha^2+\beta^2=\dfrac{21}{4} \ (see\ previous\ post)\\\\(\alpha+\beta)^4=\dfrac{625}{16} \\\\=\alpha^4+\beta^4+4*\alpha^3*\beta+6*\alpha^2*\beta^2+4*\alpha*\beta^3\\\\=\alpha^4+\beta^4+4*(\alpha*\beta)(\alpha^2+\beta^2)+6*\alpha^2*\beta^2\\\\\alpha^4+\beta^4=(\alpha+\beta)^4-4*(\alpha*\beta)(\alpha^2+\beta^2)-6*\alpha^2*\beta^2\\\\= \dfrac{625}{16} -4*\dfrac{1}{2} *\dfrac{21}{4} -6*(\dfrac{1}{2})^2 \\\\$

$= \dfrac{625}{16}- \dfrac{168}{16}-\dfrac{24}{16}\\\\\\= \dfrac{433}{16}$

7 0

3 years ago

A boat is 60m from the base of a lighthouse. The angle of depression between the lighthouse and the boat is 37°. How tall is the

LekaFEV [45]

Answer: 34.64 m

Step-by-step explanation:

Given: A boat is 60 m from the base of a lighthouse.

The angle of depression between the lighthouse and the boat is 37°.

By using trigonometric ratios :

$\tan x=\dfrac{\text{Side opposite to }x}{\text{Side adjacent to }x}$

here x= 37°, side opposite to x = height of lighthouse (h) , side adjacent to x = 60 m

$\tan 37^{\circ}=\dfrac{h}{60}\\\\\Rightarrow\ 0.57735=\dfrac{h}{60}\\\\\Rightarrow\ h= 60\times0.57735\approx34.64$

Hence, the lighthouse is 34.64 m tall.

6 0

3 years ago

The diameters of ball bearings are distributed normally. The mean diameter is 83 millimeters and the standard deviation is 3 mil

Alenkinab [10]

Answer:

0.2514 = 25.14% probability that the diameter of a selected bearing is greater than 85 millimeters.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

$\mu = 83, \sigma = 3$