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3 years ago

How do I solve for this equation 8(2x+9)=56

Mathematics

1 answer:

Step2247 [10]3 years ago

3 0

Answer:x=-1

Step-by-step explanation:Step by step solution :

Step 1 :

Equation at the end of step 1 :

8 • (2x + 9) - 56 = 0

Step 2 :

Step 3 :

Pulling out like terms :

3.1 Pull out like factors :

16x + 16 = 16 • (x + 1)

Equation at the end of step 3 :

16 • (x + 1) = 0

Step 4 :

Equations which are never true :

4.1 Solve : 16 = 0

This equation has no solution.

A a non-zero constant never equals zero.

Solving a Single Variable Equation :

4.2 Solve : x+1 = 0

Subtract 1 from both sides of the equation :

x = -1

One solution was found :

x = -1

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Answer:

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Step-by-step explanation:

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3 years ago

Which number is irrational?<br><br> A.0.3 B. C.0.777... D.0.454545…

Savatey [412]

Each of A, C, and D are rational, so presumably B is the answer here.

A is rational, since $10\times0.3=3$ , so $0.3=\dfrac3{10}$ .

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3 years ago

Find all points on the circle (x^2) + (y^2) = 676 where the slope is 5/12

borishaifa [10]

Implicit defferentation

remember that dy/dx y= dy/dx

so
take derivitive of both sides
$2x+2y \space\ \frac{dy}{dx}=0$
solve for $\frac{dy}{dx}$
minus 2x both sides
$2y \space\ \frac{dy}{dx}=-2x$
divide both sides by 2y
$\frac{dy}{dx}=\frac{-2x}{2y}$
$\frac{dy}{dx}=\frac{-x}{y}$

when is the slope equal to $\frac{5}{12}$
solve for $\frac{dy}{dx}=\frac{5}{12}$
$\frac{dy}{dx}=\frac{5}{12}$
$\frac{5}{12}=\frac{-x}{y}$
$5y=-12x$
$y=\frac{-12}{5}x$
find where the circle and this line intersects

substitute $\frac{-12}{5}x$ for y
$x^2+(\frac{-12}{5}x)^2=676$
$x^2+\frac{144}{25}x^2=676$
$\frac{25}{25}x^2+\frac{144}{25}x^2=676$
$\frac{169}{25}x^2=676$
times both sides by $\frac{25}{169}$
$x^2=100$
sqrt both sides, take positive and negative roots
x=+/-10

sub back

$y=\frac{-12}{5}x$
$y=(\frac{-12}{5})(10) \space\ or \space\ (\frac{-12}{5})(-10)$
$y=\frac{-120}{5} \space\ or \space\ \frac{120}{5}$
$y=-24 \space\ or \space\ 24$

the points are (10,-24) and (-10,24)

8 0

3 years ago

Alexa has $60 already saved and her sister Susan has $120 already saved. Alexa is saving $7 per week and her sister is saving $5

masha68 [24]

Step 1:

The variable is the number of weeks needed to equalize Alexa and her sisters savings.

Step 2:

7x + 60 = 5x + 120

Step 3:

7x+60=5x+120

Subtract 60 from both sides.

7x+(60-60)=5x+(120-60)

7x=5x+60

Subtract 5x from both sides

7x-5x=5x+60-5x

2x=60

Divide both sides by 2.

2x/2 = 60/2

x=30

Step 4:

7(30) + 60 = 5(30)+ 120

210+60=150+120

270 = 270

Step 5:

To find the unknown amount of weeks, you need to rewrite the equation isolate x on the left-hand side of the equation. I just subtracting/simplified the equation until I could solve it.

(tbh got stuck on this one)

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3 years ago

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Sergio [31]

I'm not sure what you're really talking about.

But I think you are talking about fractions.

In fractions there are two places

The number that goes on the top is numerator.

8 0

3 years ago