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2 years ago

Please help i dont understand

Mathematics

1 answer:

AlekseyPX2 years ago

6 0

Answer :

1) If x = 6

Substitute 6 for x in the expression.

a) 5x-9

5(6)-9

30-9

b) 2x-7

2(6) -7

12-7

c) 8x+5

8(6)+5

48+5

d) 4(x+3)

4(6+3)

4(9)

e) x²-(-4)

6²-(-4)

36+4

f) 3x²+1

3(6²)+1

3(36) +1

108+1

109

2) Solve

a) 54 = 3x

Divide both sides by 3.

54/3 = 3x/3

x = 18

b) x-9 = -3

Add 9 to both sides.

x-9+9 = -3+9

x = 6

c) x/7 = 140

Express the 140 over 1 and cross multiply.

x/7 = 140/1

x = 140×7

x = 980

d) x/8 = 72

Express the 72 over 1 and cross multiply.

x/8 =72/1

x = 72×8

x = 576

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4,8,12,16,20,24
6,12,18,24

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4 years ago

What quadrilateral always has 4 congruent angles and opposite sides that are congruent and parellel

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5 0

3 years ago

What is the sum of all the odd numbers from 21 to 39?

Oliga [24]

The odd numbers in between those two numbers are: 23, 25, 27, 29, 31, 33, 35, and 37. When you add them all up, you get an answer of: 240.
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Hope this helps!

7 0

3 years ago

Only answer 28 ( I added this parentheses so that the thing would accept my question)

avanturin [10]

Answer:

(a). Number of protons in a chlorine atom = 17

(b). Atomic number of sodium = 11

Step-by-step explanation:

Let the number of protons in a sodium atom = x

Then, the number of protons in a chlorine atom = x + 6

Now, it is given that the atomic number of an element is equal to the number of protons per atom.

So, atomic number of sodium (Na) = x

Atomic number of chlorine (Cl) = x + 6

It is given that the atomic number of chlorine is 5 less than twice the atomic number of sodium.

∴ atomic number of chlorine (Cl) = 2 × atomic number of sodium (Na) - 5

⇒ x + 6 = 2x - 5

⇒ x - 2x = -5 - 6

⇒ -x = -11

Cancelling the minus sign from both sides, we get

x = 11

(a). Number of protons in a chlorine atom = x + 6

= 11 + 6 (∵ x = 11)

= 17

(b). Atomic number of sodium = x = 11

3 0

3 years ago

B. {(15,0),(15,-2)} Function? Domain: Range

AlekseyPX

Answers:

Function? No, it's not a function
Domain: {15}
Range: {0, -2}

===============================================

Explanation:

The domain consists of the set of x coordinates of each point. In this case, we only have one x value listed. The domain is {15}. Use curly braces even if there's only one item. This tells the reader we have a set.

The range is {0,-2} to indicate the y coordinates of the two points.

We don't have a function because x = 15 repeats itself. The input x = 15 leads to multiple outputs at the same time, which isn't allowed if you want a function. You can use the vertical line test as a visual way to see that we don't have a function.

7 0

3 years ago

Please help i dont understand ​

Please help i dont understand