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3 years ago

2x- 3y=9 5x+3y=12 How would i solve this? I dont understand this and i really need help with it!Also I have to graph the an

wsers afterward on a graph, so i really need the help. I appreciate it:)

Mathematics

1 answer:

dedylja [7]3 years ago

7 0

$\begin{cases} 2x- 3y=9 \\5x+3y=12 \end{cases}\\ + \ \ ------- \\ 7x=21 \ \ /: 7\\ \\x=\frac{21}{3}\\ \\ x=3 \\ \\2x- 3y=9$

$2*3-3y=9\\ \\6-3y =9\\ \\-3y=9-6\\ \\-3y=3 \ \ / :(-3)\\ \\x=-1\\ \\ \begin{cases} x=3\\y= -1 \end{cases}$

$graph\\ \\\begin{cases} 2x- 3y=9 \\5x+3y=12 \end{cases}\\ \\ \begin{cases} - 3y=-2x+9\ \ /:(-3) \\ 3y=-5x+12 \ \ /:3 \end{cases}\\ \\ \begin{cases} y= \frac{2}{3}x-3 \\ y=-\frac{5}{3}x+4 \end{cases}$

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bagirrra123 [75]

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3 years ago

What is -3 - 9n= 42 I can’t be negative

maw [93]

If you were to correctly simplify this equation, the answer would be a negative.

The answer is: n = -5

Here's how I got my answer:

Step 1: Add 3 to both sides. Which leaves us with $-9n=42+3$

Step 2: Simplify $42+3$ to 45. Which leaves us with $-9n = 45$

Step 3: Divide both sides by -9. Which leaves us with $n = -45/9$

Step 4: Simplify $-45/9$ , to get your answer, n = -5.

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3 years ago

100 POINTS!!! Which statement about rational numbers is correct?

Natasha_Volkova [10]

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Step-by-step explanation:

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2 years ago

Part of the proceeds from a garage sale was $470 worth of $10 and $20 bills. If there were 14 more $10 bills than $20 bills, fin

Brums [2.3K]

There are 25 $10 bills and 11 $20 bills.

Step-by-step explanation:

Given,

Worth of proceeds from garage = $470

Let,

x be the number of $10 bills

y be the number of $20 bills.

According to given situation;

10x+20y=470 Eqn 1

x = y+14 Eqn 2

Putting value of x from Eqn 2 in Eqn 1

$10(y+14)+20y=470\\10y+140+20y=470\\30y=470-140\\30y=330$

Dividing both sides by 30

$\frac{30y}{30}=\frac{330}{30}\\y=11$

Putting y=11 in Eqn 2

$x=11+14\\x=25$

There are 25 $10 bills and 11 $20 bills.

Keywords: linear equation, substitution method

Learn more about linear equations at:

#LearnwithBrainly

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2 years ago

The school purchased baseball equipment and uniforms for a total cost of $1836. the equipment cost $612 and the uniforms were $2

liraira [26]

Answer:

48 uniforms

Step-by-step explanation:

1836-612=1224.

1224/25.50=48.

Checked answer:

25.50 x 48= 1224

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3 years ago