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3 years ago

Help meh plz for brainlist

Mathematics

1 answer:

yanalaym [24]3 years ago

8 0

Answer:

Step-by-step explanation:

(pemdas) 3 3^2 9 x 3 = 27 - 13

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Can someone help me with 5-9 please?!?!? Thank you

valina [46]

5 is 1!!!!!!

Step-by-step explanation:

im sorry i dont know the others

3 0

1 year ago

What is 8/12 + A/12=2/b

il63 [147K]

Answer:

the answer i got was a=−8b+24/b

Step-by-step explanation:

hoped I helped:)

8 0

3 years ago

<img src="https://tex.z-dn.net/?f=%5Cleft%20%5C%7B%20%7B%7Bx%2By%3D1%7D%20%5Catop%20%7Bx-2y%3D4%7D%7D%20%5Cright.%20%5C%5C%5Clef

brilliants [131]

Answer:

(a) x=2, y=-1

(b) x=2, y=2

(c) $\displaystyle x=\frac{5}{2}, y=\frac{5}{4}$

(d) x=-2, y=-7

Step-by-step explanation:

Cramer's Rule

It's a predetermined sequence of steps to solve a system of equations. It's a preferred technique to be implemented in automatic digital solutions because it's easy to structure and generalize.

It uses the concept of determinants, as explained below. Suppose we have a 2x2 system of equations like:

$\displaystyle \left \{ {{ax+by=p} \atop {cx+dy=q}} \right.$

We call the determinant of the system

$\Delta=\begin{vmatrix}a &b \\c &d \end{vmatrix}$

We also define:

$\Delta_x=\begin{vmatrix}p &b \\q &d \end{vmatrix}$

And

$\Delta_y=\begin{vmatrix}a &p \\c &q \end{vmatrix}$

The solution for x and y is

$\displaystyle x=\frac{\Delta_x}{\Delta}$

$\displaystyle y=\frac{\Delta_y}{\Delta}$

(a) The system to solve is

$\displaystyle \left \{ {{x+y=1} \atop {x-2y=4}} \right.$

Calculating:

$\Delta=\begin{vmatrix}1 &1 \\1 &-2 \end{vmatrix}=-2-1=-3$

$\Delta_x=\begin{vmatrix}1 &1 \\4 &-2 \end{vmatrix}=-2-4=-6$

$\Delta_y=\begin{vmatrix}1 &1 \\1 &4 \end{vmatrix}=4-3=3$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{-6}{-3}=2$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{3}{-3}=-1$

The solution is x=2, y=-1

(b) The system to solve is

$\displaystyle \left \{ {{4x-y=6} \atop {x-y=0}} \right.$

Calculating:

$\Delta=\begin{vmatrix}4 &-1 \\1 &-1 \end{vmatrix}=-4+1=-3$

$\Delta_x=\begin{vmatrix}6 &-1 \\0 &-1 \end{vmatrix}=-6-0=-6$

$\Delta_y=\begin{vmatrix}4 &6 \\1 &0 \end{vmatrix}=0-6=-6$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{-6}{-3}=2$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{-6}{-3}=2$

The solution is x=2, y=2

$\displaystyle \left \{ {{-x+2y=0} \atop {x+2y=5}} \right.$

Calculating:

$\Delta=\begin{vmatrix}-1 &2 \\1 &2 \end{vmatrix}=-2-2=-4$

$\Delta_x=\begin{vmatrix}0 &2 \\5 &2 \end{vmatrix}=0-10=-10$

$\Delta_y=\begin{vmatrix}-1 &0 \\1 &5 \end{vmatrix}=-5-0=-5$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{-10}{-4}=\frac{5}{2}$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{-5}{-4}=\frac{5}{4}$

The solution is

$\displaystyle x=\frac{5}{2}, y=\frac{5}{4}$

(d) The system to solve is

$\displaystyle \left \{ {{6x-y=-5} \atop {4x-2y=6}} \right.$

Calculating:

$\Delta=\begin{vmatrix}6 &-1 \\4 &-2 \end{vmatrix}=-12+4=-8$

$\Delta_x=\begin{vmatrix}-5 &-1 \\6 &-2 \end{vmatrix}=10+6=16$

$\Delta_y=\begin{vmatrix}6 &-5 \\4 &6 \end{vmatrix}=36+20=56$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{16}{-8}=-2$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{56}{-8}=-7$

The solution is x=-2, y=-7

4 0

3 years ago

Shawna found coins worth $4.32. One- fourth of the found coins are pennies and one- sixth are quarters. The number of nickels fo

eduard

Answer:

8 quarters

12 nickels

12 pennies

16 dimes

Step-by-step explanation:

The trick is to ASSUME the dimes.

Start by thinking about the three explicit premises and the one implicit premise.

1) Quarters = 1/6 of total coins

2) Nickels = 1.5 the number of quarters

3) Pennies = 1/4 of total coins

Also, ASSUME an unknown number of dimes to fill in the gap.

48 Total Coins = $4.32

⅙ of 48 = 8 8 quarters = $2.00

1.5 x 8 = 12 12 nickels = $0.60

¼ of 48 = 12 12 pennies = $0.12

Add those coins = $2.72

Take the known total and minus this sum.

$4.32 - $2.72 = $1.60

16 dimes = $1.60

Thus, you have the following:

8 quarters (⅙ of total coins) $2.00

12 nickels (1.5 the number of quarters) $0.60

12 pennies (¼ the number of total coins) $0.12

+ 16 dimes $1.60

Total Coins 48 $4.32

8 0

3 years ago

Eaches seven science classes. He needs 12 liters of water for each class to perform an upcoming experiment. How many milliliters

Angelina_Jolie [31]

Answer:

Step-by-step explanation:

7 × 12 = 84

84 × 1000 = 84000

84000 mililetre

7 0

3 years ago