MATHEMATICS MIDDLE SCHOOL

5x+7y=775x+3y=53



2x+5y=-1
X+2y=0


3x+6y=6
2x-3y=4

Answers

Answer 1
Answer: 1.)
5x+7y=77\n 5x+3y=53\n (5x+7y)-(5x+3y)=77-53\n 5x-5x+7y-3y=24\n 4y=24\n y=6\n 5x+7\cdot 6=77\n 5x+42=77\n 5x=77-42\n 5x=35\n x=\frac { 35 }{ 5 } \n x=7

2.)
2x+5y=-1\n x+2y=0\n \n 2\cdot (x+2y)=2\cdot 0\n 2x+4y=0\n (2x+5y)-(2x+4y)=-1-0\n 2x-2x+5y-4y=-1\n y=-1\n 2x+5\cdot -1=-1\n 2x-5=-1\n 2x=-1+5\n 2x=4\n x=\frac { 4 }{ 2 } \n x=2

3.)3x+6y=6\n 2x-3y=4\n 2\cdot (2x-3y)=2\cdot 4\n 4x-6y=8\n \n (3x+6y)+(4x-6y)=6+8\n 4x+3x+6y-6y=14\n 7x=14\n x=\frac { 14 }{ 7 } \n x=2\n \n 3\cdot 2+6y=6\n 6+6y=6\n 6y=0\n y=0\n

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Which of the following options have the same value as 65%, percent of 20?

Answers

This question is incomplete. Hereis the complete question:

Which of the following options have the same value as 65% of 20?

(A) 0.65⋅20 (B) 65/100 divided by 20 (C) 65/20 * 100 (D) 65 * 20

Answer:

The correct answer is option (A) 0.65⋅20

Step-by-step explanation:

In this case they are asking us for an expression that is equivalent to 65% of 20. They are not asking us what is the value of that operation.

When we do a percentage calculation we can do it in two ways.

Let's see each one of them:

. (65 * 20): 100 =

  1300: 100 = 13

. 0.65. 20 = 13

As we can see both ways we get the same result.

Given this information we can say that the correct answer is option A.

Answer:

13

Step-by-step explanation:

You find out what is one percent then multiply from there

Wich is greater 500 seconds or 8 minutes

Answers

500 seconds is greater. Since there are 60 seconds in one minute you would multiply 60 and 8. 
60x8= 480
500 seconds because 8 sixty times is 480 so 500 is greater

Solve each quadratic equation by factoring. 6n^2-18n-18=6

Answers

Divide by 6 to get:

n^2-3n-3=1

Subtracting 1, we see that:

n^2-3n-4=0

Factoring, we have:

(n-4)(n+1)=0

Therefore, 4 and -1 are the solutions, since if either n-4 or n+1 is zero, the whole expression is zero.
6n^(2)-18n-18=6 \n \n 6n^(2)-18n-24=0 \n \n 6(n^(2)-3n-4)=0 \n \n n^(2)-3n-4=0 \n \n n^(2)-4n+n-4=0 \n \n n(n-4)+(n-4)=0 \n \n (n+1)(n-4)=0 \n \n n+1=0 \ \vee \ n-4=0 \n \n n=-1 \ \vee \ n=4 \n \n n\in \lbrace -1,4 \rbrace

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When is the nearest whole number to 3.2

Answers

Its 3. Since 2 is a small number, lower than 5, so you round down to 3
the nearest whole #umber is three

What is 3.2 + 6.1 - -1

Answers

Answer:

10.3

Step-by-step explanation:

3.2+6.1=9.3

-(-1) is 1

So 9.3+1=10.3
You the double negative makes the 1 a positive. 10.3

I have 3 hundreds,17 tens,13 ones,1 tenths,and 2 hundredths.what number am i?

Answers

301.172 because you did to know there is no suck ting at ones have that you did to add all them up.
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