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2 years ago

If x + y = 10 and x - y = 4, find the value of x² - y²

Mathematics

2 answers:

morpeh [17]2 years ago

8 0

Answer:

x²-y² = 40

Step-by-step explanation:

Factorising x²-y²:

x²-y² = (x+y)(x-y)

This is due to the property that states:

a²+b² = (a+b)(a-b)

Substituting the given values into the above equation:

x²-y² = (10)(4)

= 40

Hence, x²-y² = 40

<em>Hope this helps and be sure to have a wonderful time ahead at Brainly! :D</em>

kondaur [170]2 years ago

3 0

Answer:

x² - y²=40 or 7²-3²=40

Step-by-step explanation:

if x=7 that would make y=3

7+3=10 and 7-3=4

7x7=49

3x3=9

49-9=40

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Logan took out $23,400 in student loans to attend college at a compound interest rate of 5%. He deferred payments for two years.

blagie [28]

Answer:

$25,740

Step-by-step explanation:

First, converting R percent to r a decimal

r = R/100 = 5%/100 = 0.05 per year,

then, solving our equation

I = 23400 × 0.05 × 2 = 2340

I = $ 2,340.00

The simple interest accumulated

on a principal of $ 23,400.00

at a rate of 5% per year

for 2 years is $ 2,340.00.

8 0

2 years ago

PLEASE HELP ME PRE CAL/TRIG

miss Akunina [59]

Answer:

A) 60 Degrees

B) 550 Feet

C) 2.5 minutes

Step-by-step explanation:

a) So the wheel has completed one revolution in 10 minutes so lets first divide 100 secs with 10 minutes to calculate the the fraction of revolution

1 min = 60 secs

10 min = 600 secs

100/600 = 1/6

One complete revolution is 360 degrees and 1/6 of 360 degrees will be 60 degrees .

360/6 = 60°

b) It takes 10 minutes to complete one revolution so if the person is on it for 7 minutes it would be 7/10 of a revolution . The ferris wheel has a diameter of 250 feet so the radius will be 125 feet because it is the half of the diameter and the circumference will be 250 π . To calculate the distance lets multiple the fraction of the revolution which is 7/10 into the circumference $\frac{7}{10} * (250 pi)$ = 550 Feet.

C)It took 10 minutes to travel 250 π now we will use this relation to calculate 200 feet . lets suppose t is for time .

$\frac{250pi}{10} =\frac{200}{t}$ .

After solving this equation as there is only one unknown which is "<em>t</em> "the answer will be 2.5 minutes.

3 0

3 years ago

what is the correct upper and lower control limits for 8.42 pounds and the accectable range for plus or minus .65 pounds

sweet [91]

Answer:

9.07 and 7.77 respectively.

Step-by-step explanation:

To determine the upper control limit, add 0.65 lb to 8.42 lb, obtaining 9.07 lb.

To determine the lower one, subtract 0.65 lb from 8.42 lb, obtaining 7.77 lb.

7 0

3 years ago

Example 2

PIT_PIT [208]

Answer: (a) 314.2cm², (b) 157.1cm², (c) 78.55cm² (e) 6.77

Step-by-step explanation: (a) Area of the circle with radius of 10 cm = πr²

= 3.142 × 10 × 10

= 3.142 × 100

= 314.2cm²

The formula = πr²

(b) Area of the half of a circle known as semicircle

= πr²/2

= 3.142 ×10 × 10/2

= 3.142 × 50

= 157.1cm²

The formula = πr²/2

= πr²/4

= 3.142 × 10 × 10/4

= 314.2/4

= 78.55cm²

The formula is written thus = πr²/4, which implies that the circle is divided into 4 unit

(d) The conjecture about how to determine the area of the sector is

Formula of a sector = ∅/360(πr²)

<u>Information</u>

The arc cant be 60°, therefore information incomplete.

(e) Area of the sector with the angle AOB of 60° = 24.

To find the radius of the angle, make v the subject of the formula from the formula.

Sector area = πr²∅/360°

equate formula to 24.

Therefore πr²∅/360° = 24

Multiply through by360° to make it a linear expression

It now becomes πr²∅ =24× 360°

r² = 24 x 360/π × ∅°

r² = 24 × 360° /3.142 × 60°

r² = 3,640/188.52

r² = 45.8

To find r , we take the square root of both side by applying laws of indicies

Therefore r = √45 .8

r = 6.77

(f) General formula = ∅°/360° × (πr²)

angle substended at centre by the arc = x°

assuming the radius of the circle = ycm, Therefore, area of the sector = { ∅°/360° × πy² }

8 0

2 years ago

Using the double number line shown, for the equation 5x+4=14, what is the value of x?

Alex777 [14]

Correct option is:

B. 2

<h2>Explanation:</h2>

From the double number line shown we can set:

$(1) \ 0x=0 \\ \\ (2) \ x=? \\ \\ (3) \ 5x=10 \\ \\ (4) \ 5x+4=14$

So we can solve this problem by using either equation (3) or (4). So, choosing equation (3):

$5x=10 \\ \\ \\ Divide \ both \ sides \ by \ 5: \\ \\ x=\frac{10}{5} \\ \\ \boxed{x=2}$

<h2>Learn more:</h2>

Solving equations: brainly.com/question/7747308

#LearnWithBrainly

3 0

2 years ago