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3 years ago

What is the average percentage of 48 and 80

Mathematics

1 answer:

vlabodo [156]3 years ago

8 0

I know this is probably too late but its 60%

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How do i write equation using points (0,1) and (4,0)

mafiozo [28]

Answer:

its y= - 1/4x + 1

hope this helps

Step-by-step explanation:

5 0

3 years ago

Solve for x: 4 over x plus 4 over quantity x squared minus 9 equals 3 over quantity x minus 3. (2 points) Select one: a. x = -4

Kay [80]

Answer:

Step-by-step explanation:

$\dfrac{4}{x}+\dfrac{4}{x^2-9}=\dfrac{3}{x-3}$

Domain:

$x\neq0\ \wedge\ x^2-9\neq0\ \wedge\ x-3\neq0\\\\x\neq0\ \wedge\ x\neq\pm3$

solution:

$\dfrac{4}{x}+\dfrac{4}{x^2-3^2}=\dfrac{3}{x-3}$

use <em>(a - b)(a + b) = a² - b²</em>

$\dfrac{4}{x}+\dfrac{4}{(x-3)(x+3)}=\dfrac{3}{x-3}$

multiply both sides by (x - 3) ≠ 0

$\dfrac{4(x-3)}{x}+\dfrac{4(x-3)}{(x-3)(x+3)}=\dfrac{3(x-3)}{x-3}$

cancel (x - 3)

$\dfrac{4(x-3)}{x}+\dfrac{4}{x+3}=3$

subtract $\frac{4(x-3)}{x}$ from both sides

$\dfrac{4}{x+3}=3-\dfrac{4(x-3)}{x}\\\\\dfrac{4}{x+3}=\dfrac{3x}{x}-\dfrac{(4)(x)+(4)(-3)}{x}\\\\\dfrac{4}{x+3}=\dfrac{3x-\bigg(4x-12\bigg)}{x}\\\\\dfrac{4}{x+3}=\dfrac{3x-4x-(-12)}{x}\\\\\dfrac{4}{x+3}=\dfrac{-x+12}{x}$

cross multiply

$(4)(x)=(x+3)(-x+12)$

use FOIL

$4x=(x)(-x)+(x)(12)+(3)(-x)+(3)(12)\\\\4x=-x^2+12x-3x+36$

subtract 4x from both sides

$0=-x^2+12x-3x+36-4x$

combine like terms

$0=-x^2+(12x-3x-4x)+36\\\\0=-x^2+5x+36$

change the signs

$x^2-5x-36=0\\\\x^2-9x+4x-36=0\\\\x(x-9)+4(x-9)=0\\\\(x-9)(x+4)=0$

The product is 0 if one of the factors is 0. Therefore:

$x-9=0\ \vee\ x+4=0$

$x-9=0$ <em>add 9 to both sides</em>

$x=9\in D$

$x+4=0$ <em>subtract 4 from both sides</em>

$x=-4\in D$

7 0

3 years ago

John says that 0.5y for y=1.4 is 0.7<br> Is he correct? Explain.<br> 17 points

Alona [7]

John is correct because 0.5 is equal to one half and multiplying something by its half is just same as dividing something in two and half of 1.4 is 0.5

(sorry if it's too long feel free to shorten it)

7 0

3 years ago

Read 2 more answers

Two pencils and a ruler cost 98 cents in total. One pencil and 2 rulers cost $1.24 in total. Find the cost of each item.

salantis [7]

Answer:

2.16

Step-by-step explanation:

r = cost of ruler

p = cost of pencil

r = 2p

6r + 15p = 2.16