Respuesta :

gmany

[tex]\dfrac{1}{3}x=6-\dfrac{1}{5}x\qquad\text{multiply both sides by 15}\\\\15\cdot\dfrac{1}{3}x=15\cdot6-15\cdot\dfrac{1}{5}x\\\\5x=90-3x\qquad\text{add 3x to both sides}\\\\8x=90\qquad\text{divide both sides by 8}\\\\x=\dfrac{90}{8}\\\\x=\dfrac{45}{4}\\\\x=11\dfrac{1}{4}\to x=11.25[/tex]

jcherry99

(1/3)x = 6 - (1/5)x   Add (1/5) x to both sides.

(1/3)x + (1/5)x = 6  Find the Lowest common denominator of 1/3 and 1/5. Both are primes.

3 has 3 as a part of the LCD.

5 has 5 as part of the LCD

LCD: 3 * 5  The LCM is the number of needed primes (3 and 5 in this case) multiplied together.

LCD: 15

1/3 = 1 * 5 / (3 * 5) = 5/15      Equivalent to 1/3

1/5 = 1 * 3 /  (3 * 5) = 3/15     Equivalent to 1/5

(5/15)x + (3/15)x = 6              Add the fractions

(8/15)x = 6                            Change 8/15 to a decimal

0.53333333 x = 6               Divide by 0.5333333 on both sides.

x = 6/ 0.533333333            Make sure you use as much of the repeating decimal as you can. This method saves you having to divide by a fraction.

x = 11.25        



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