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3 years ago

5

Cynthia can wallpaper a room in 4 hours and her brother can do it in 6 hours. How long would it take them if they work together

1 answer:

Debora [2.8K]3 years ago

3 0

Answer:

2 hours and 24 minutes

Step-by-step explanation:

cynthia can wallpaper a room 4 hours with means in 1 hour she can wallpaper 1/4th of the room, her brother can wallpaper the same room in 6 hours so I'm 1 hour he can wallpaper 1/6 of the room.

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Help please is for Algebra

Sauron [17]

Answer:

$=\frac{8a+6}{\left(a-3\right)\left(a+3\right)}$

the third option is your answer

Step-by-step explanation:

$\frac{5}{a-3}+\frac{3}{a+3}\\\mathrm{Least\:Common\:Multiplier\:of\:}a-3,\:a+3:\quad \left(a-3\right)\left(a+3\right)\\\mathrm{Adjust\:Fractions\:based\:on\:the\:LCM}\\=\frac{5\left(a+3\right)}{\left(a-3\right)\left(a+3\right)}+\frac{3\left(a-3\right)}{\left(a+3\right)\left(a-3\right)}\\\mathrm{Since\:the\:denominators\:are\:equal,\:combine\:the\:fractions}:\quad \frac{a}{c}\pm \frac{b}{c}=\frac{a\pm \:b}{c}\\=\frac{5\left(a+3\right)+3\left(a-3\right)}{\left(a-3\right)\left(a+3\right)}$

$\mathrm{Expand}\:5\left(a+3\right)+3\left(a-3\right):\quad 8a+6\\=\frac{8a+6}{\left(a-3\right)\left(a+3\right)}$

6 0

3 years ago

Let f(x) be defined for any positive integer x greater than 2 as the sum of all prime numbers less than x. For example, f(4)=2+3

blsea [12.9K]

Answer:

f(86)-f(82)

Step-by-step explanation:

well f of 82 = 2 plus _ plus _ plus _ and f of 86 is 2+_+_+_ subtract them

(A) 3 (B) 4 (C) 47 (D) 59 (E) 83

these are some possible answers so the answer is b, 4

btw, 86-82 = 4 duh

7 0

3 years ago

Read 2 more answers

Determine the correct set up for solving the equation using the<br> quadratic formula 4x^2-5=3x+4

slava [35]

You need to subtract everything to the left side and set it equal to zero. Combine like terms.

Then, the coefficient of x^2 is a, the coefficient of x is b, and the constant term is c.

4x^2 - 5 = 3x + 4

4x^2 - 3x - 5 - 4 = 0

4x^2 - 3x - 9 = 0

a = 4; b = -3; c = -9

$x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

$x = \dfrac{-(-3) \pm \sqrt{(-3)^2 - 4(4)(-9)}}{2(4)}$

7 0

3 years ago

What is 5/6 minus 1/6

patriot [66]

5/6 minus 1/6 is 2/3

6 0

3 years ago

Read 2 more answers

Solve. x 2 −5x−8=0 x2−5x−8=0 Enter your answers, as exact values, in the boxes. x = or x =

Sidana [21]

Answer:

x2-5x-8=0

Step-by-step explanation:

Two solutions were found :

x =(5-√57)/2=-1.275

x =(5+√57)/2= 6.275

Reformatting the input :

Changes made to your input should not affect the solution:

(1): "x2" was replaced by "x^2".

Step by step solution :

Step 1 :

Trying to factor by splitting the middle term

1.1 Factoring x2-5x-8

The first term is, x2 its coefficient is 1 .

The middle term is, -5x its coefficient is -5 .

The last term, "the constant", is -8

Step-1 : Multiply the coefficient of the first term by the constant 1 • -8 = -8

Step-2 : Find two factors of -8 whose sum equals the coefficient of the middle term, which is -5 .

-8 + 1 = -7

-4+ 2 = -2

-2+ 4 = 2

-1 + 8 = 7

5 0

3 years ago

Read 2 more answers