Mister Exam
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How to use it?
- Equation:
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Equation cos(x)=-2
- Equation (m+8)*(m-7)=0
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Equation sin(5x)=-1/2
- Equation 640÷(x×9+8)=8
- Express {x} in terms of y where:
- 16*x-20*y=-4
- -11*x+4*y=-8
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Identical expressions
- six hundred and forty ÷(x× nine + eight)= eight
- 640÷(x×9 plus 8) equally 8
- six hundred and forty ÷(x× nine plus eight) equally eight
- 640÷x×9+8=8
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Similar expressions
- 640÷(x×9-8)=8
640÷(x×9+8)=8 equation
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The solution
Detail solution
Given the equation:
$$\frac{640}{9 x + 8} = 8$$
Use proportions rule:
From a1/b1 = a2/b2 should a1*b2 = a2*b1,
In this case
so we get the equation
$$\frac{640}{8} = 9 x + 8$$
$$80 = 9 x + 8$$
Move free summands (without x)
from left part to right part, we given:
$$0 = 9 x - 72$$
Move the summands with the unknown x
from the right part to the left part:
$$\left(-9\right) x = -72$$
Divide both parts of the equation by -9
We get the answer: x = 8
$$\frac{640}{9 x + 8} = 8$$
Use proportions rule:
From a1/b1 = a2/b2 should a1*b2 = a2*b1,
In this case
a1 = 640
b1 = 8 + 9*x
a2 = 1
b2 = 1/8
so we get the equation
$$\frac{640}{8} = 9 x + 8$$
$$80 = 9 x + 8$$
Move free summands (without x)
from left part to right part, we given:
$$0 = 9 x - 72$$
Move the summands with the unknown x
from the right part to the left part:
$$\left(-9\right) x = -72$$
Divide both parts of the equation by -9
x = -72 / (-9)
We get the answer: x = 8