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Zorluk: ZorLinear Equations in One Variable

In the equation below, aa is a constant.

13(ax2)12(x4a)=3x5 \frac{1}{3}(ax - 2) - \frac{1}{2}(x - 4a) = 3x - 5

If the solution to the equation is x=2x = 2, what is the value of aa?

  1. A
    2-2
  2. B
    12\frac{1}{2}
  3. 11Cevap
  4. D
    22

Cevap

1
Substituting x=2x = 2 into the equation gives 13(2a2)12(24a)=3(2)5\frac{1}{3}(2a - 2) - \frac{1}{2}(2 - 4a) = 3(2) - 5, which simplifies to 13(2a2)(12a)=1\frac{1}{3}(2a - 2) - (1 - 2a) = 1. Multiplying the entire equation by 3 to clear the fraction yields (2a2)3(12a)=3(2a - 2) - 3(1 - 2a) = 3. Distributing the negative 3 yields 2a23+6a=32a - 2 - 3 + 6a = 3, which simplifies to 8a5=38a - 5 = 3. Adding 5 to both sides results in 8a=88a = 8, which gives a=1a = 1.

Adım Adım Çözüm

1
Substitute x=2x = 2 into the given equation.
13(2a2)12(24a)=3(2)5\frac{1}{3}(2a - 2) - \frac{1}{2}(2 - 4a) = 3(2) - 5
Since x=2x = 2 is a solution to the equation, substituting it into the equation must yield a true mathematical statement.
2
Simplify the constant terms and distribute or simplify the expressions.
13(2a2)(12a)=1\frac{1}{3}(2a - 2) - (1 - 2a) = 1
Simplifying 3(2)53(2) - 5 yields 11, and simplifying the second fraction term gives 12(24a)=12a\frac{1}{2}(2 - 4a) = 1 - 2a.
3
Multiply the entire equation by 3 to eliminate the fraction.
(2a2)3(12a)=3(2a - 2) - 3(1 - 2a) = 3
Multiplying all terms on both sides of the equation by the denominator 3 clears the fraction and simplifies the equation.
4
Distribute the negative 3 and combine like terms to solve for aa.
2a23+6a=3    8a5=3    8a=8    a=12a - 2 - 3 + 6a = 3 \implies 8a - 5 = 3 \implies 8a = 8 \implies a = 1
Distributing 3(12a)-3(1 - 2a) yields 3+6a-3 + 6a. Combining like terms gives 8a5=38a - 5 = 3, and adding 5 followed by dividing by 8 isolates the variable aa.

Anahtar Kavram

Solving linear equations in one variable containing fractions and constant parameters by substitution and term isolation.
Tahmini Süre:2m 0s
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