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oksian1 [2.3K]
3 years ago
14

a student says that if 5x2 = 20, then x must be equal to 2. do you agree or disagree with the student? justify your answer.

Mathematics
2 answers:
PtichkaEL [24]3 years ago
5 0

To check if the student is correct, we are going to solve the equation step by step.

Step 1 divide both sides of the equation by 5:

5x^2=20

\frac{5x^2}{5} =\frac{20}{5}

x^2=4

Step 2 take square root to both sides of the equation:

\sqrt{x^2} =(+/-)\sqrt{4}

x=(+/-)\sqrt{4}

x=2 or x=-2

The equation has tow solutions, x=2 and x=-2.

I disagree with the student because x=2 is just one solution and not the only one; x=-2 is also a valid solution of the equation.

forsale [732]3 years ago
5 0
I disagree. If each side of the equation is divided by 5, the result is x2 = 4. By the square root property of equality, x = -2 or x = 2. So x could be -2 instead of 2.
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Answer:

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r = radius

h = height

The Pythagorean theorem, a^2 + b^2 = c^2, will be needed to find the height.

Plug in the values.

a(unknown)^2 + 6^2 = 15^2

A + 36 = 255

255 - 36 = 189

√189 ≈ 13.7

Surface area formula, plug in the values.

A = 3.14 × 6 ( 6 + √6^2 + 13.7^2 )

*PEMDAS*

A = 3.14 × 6 ( 6 + √36 + 187.69 )

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3 years ago
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Answer:

$1,281.00

Step-by-step explanation:

We start by calculating the value $50 added each month after the first month

= $50 × 11

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Calculation:

First, converting R percent to r a decimal

r = R/100 = 5.5%/100 = 0.055 per year.

P = Principal = 500 + 550

= $1050

Calculation:

First, converting R percent to r a decimal

r = R/100 = 5.5%/100 = 0.055 per year.

Solving our equation:

A = 1050(1 + (0.055 × 4)) = 1281

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6 0
3 years ago
3/4x=-18 what is the answer?
Afina-wow [57]

Answer:

X= 24

Step-by-step explanation:

Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :

                    3/4*x-(18)=0

Step by step solution :

Step  1  :

           3

Simplify   —

           4

Equation at the end of step  1  :

  3        

 (— • x) -  18  = 0

  4        

Step  2  :

Rewriting the whole as an Equivalent Fraction :

2.1   Subtracting a whole from a fraction

Rewrite the whole as a fraction using  4  as the denominator :

         18     18 • 4

   18 =  ——  =  ——————

         1        4  

Equivalent fraction : The fraction thus generated looks different but has the same value as the whole

Common denominator : The equivalent fraction and the other fraction involved in the calculation share the same denominator

Adding fractions that have a common denominator :

2.2       Adding up the two equivalent fractions

Add the two equivalent fractions which now have a common denominator

Combine the numerators together, put the sum or difference over the common denominator then reduce to lowest terms if possible:

3x - (18 • 4)     3x - 72

—————————————  =  ———————

      4              4  

Step  3  :

Pulling out like terms :

3.1     Pull out like factors :

  3x - 72  =   3 • (x - 24)

Equation at the end of step  3  :

 3 • (x - 24)

 ————————————  = 0

      4      

Step  4  :

When a fraction equals zero :

4.1    When a fraction equals zero ...

Where a fraction equals zero, its numerator, the part which is above the fraction line, must equal zero.

Now,to get rid of the denominator, Tiger multiplys both sides of the equation by the denominator.

Here's how:

 3•(x-24)

 ———————— • 4 = 0 • 4

    4    

Now, on the left hand side, the  4  cancels out the denominator, while, on the right hand side, zero times anything is still zero.

The equation now takes the shape :

  3  •  (x-24)  = 0

Equations which are never true :

4.2      Solve :    3   =  0

This equation has no solution.

A a non-zero constant never equals zero.

Solving a Single Variable Equation :

4.3      Solve  :    x-24 = 0

Add  24  to both sides of the equation :

                     x = 24

One solution was found :

                  x = 24

6 0
3 years ago
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