All categories

2 years ago

HELP PLEASE ! 12) 12 13 + 2) + 9= ?

Mathematics

2 answers:

Dmitrij [34]2 years ago

7 0

I think I’ll be 11.4

valkas [14]2 years ago

6 0

Answer:

11.9230769231

Step-by-step explanation:

Don't ask I am a smarty

You might be interested in

A crew consists of 1 apprentice, 1 journeyman, and 1 master carpenter. The crew receives a check for $4800 for a job they jus

tamaranim1 [39]

Answer:

Apprentice=$800

Journeyman=$1600

Master=$2400

Step-by-step explanation:

We have that all the crew won a total of $4800 then it is the salary of the apprentice, the journeyman and the master carpenter. It say that the journeyman makes 200% of the apprentice, then it means that the journeyman won the double of the apprentice. The master won 150% of what a journeyman, it means that the master won 1.5 of the salary of the journeyman.

With this information we can write the next set of equations.

$A+J+M=\$4800\\J=2A\\M=1.5J$

Using the second equation in the third equation we can know how much won the master in terms of the salary of the apprentice, then:

$M=1.5J\\M=1.5(2A)\\M=3A$

With this we could rewrite the first equation as:

$A+J+M=\$4800\\A+2A+3A=\$4800\\6A=\$4800\\A=\dfrac{\$4800}{6}\\A=\$800$

Then the aprentice earn $800, the journeyman $1600 and the master $2400

6 0

2 years ago

Let a and b be roots of x² - 4x + 2 = 0. find the value of a/b² +b/a²

erastovalidia [21]

Answer:

$\dfrac{a}{b^2}+\dfrac{b}{a^2}=10$

Step-by-step explanation:

Given equation: $x^2-4x+2=0$

The roots of the given quadratic equation are the values of x when $y=0$ .

To find the roots, use the quadratic formula:

$x=\dfrac{-b \pm \sqrt{b^2-4ac} }{2a}\quad\textsf{when }\:ax^2+bx+c=0$

Therefore:

$a=1, \quad b=-4, \quad c=2$

$\begin{aligned}\implies x & =\dfrac{-(-4) \pm \sqrt{(-4)^2-4(1)(2)}}{2(1)}\\& =\dfrac{4 \pm \sqrt{8}}{2}\\& =\dfrac{4 \pm 2\sqrt{2}}{2}\\& =2 \pm \sqrt{2}\end{aligned}$

$\textsf{Let }a=2+\sqrt{2}$

$\textsf{Let }b=2-\sqrt{2}$

Therefore:

$\begin{aligned}\implies \dfrac{a}{b^2}+\dfrac{b}{a^2} & = \dfrac{2+\sqrt{2}}{(2-\sqrt{2})^2}+\dfrac{2-\sqrt{2}}{(2+\sqrt{2})^2}\\\\& = \dfrac{2+\sqrt{2}}{6-4\sqrt{2}}+\dfrac{2-\sqrt{2}}{6+4\sqrt{2}}\\\\& = \dfrac{(2+\sqrt{2})(6+4\sqrt{2})+(2-\sqrt{2})(6-4\sqrt{2})}{(6-4\sqrt{2})(6+4\sqrt{2})}\\\\& = \dfrac{12+8\sqrt{2}+6\sqrt{2}+8+12-8\sqrt{2}-6\sqrt{2}+8}{36+24\sqrt{2}-24\sqrt{2}-32}\\\\& = \dfrac{40}{4}\\\\& = 10\end{aligned}$