Question

3/4=6/x x = !!!!PLEASE HELP I WILL MARK BRAINLIEST!!!!

Answer 1

Answer:

x=8

Step-by-step explanation:

You cross multiply, 6 times 4 is 24, so what times 3 is 24. 8 times 3 is 24.

Answer 2

Answer:

  x = 8

Step-by-step explanation:

There are several ways you can solve a proportion like this. Most of the algebraic solutions involve what amounts to multiplying both sides by (4x/3). There are also graphical solutions and solutions that rely on relations that make fractions be equal.

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cross multiplication

The method of solution usually recommended is to "clear fractions" and then solve the resulting one-step linear equation. To "clear fractions," multiply both sides of the equation by the least common denominator: 4x.

  $(4x)\dfrac{3}{4}=(4x)\dfrac{6}{x}\\\\3\cdot x=4\cdot6\qquad\text{looks like "cross multiplication"}$

We describe this as "cross-multiplication" because it looks like each numerator has been multiplied by the opposite denominator.

This "one-step" linear equation is solved by dividing by the coefficient of x, which is 3:

  $\dfrac{3x}{3}=\dfrac{4\cdot6}{3}\\\\\boxed{x=8}\qquad\text{simplify}$

Note that we could have done these operations in one step. The two steps, multiply by 4x and divide by 3, are identical to the one step, multiply by (4x/3).

  $\left(\dfrac{4x}{3}\right)\cdot\dfrac{3}{4}=\left(\dfrac{4x}{3}\right)\cdot\dfrac{6}{x}\\\\\boxed{x=8}\qquad\text{simplify}$

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compare fractions

We can see the solution almost immediately if we rewrite the fractions so they have the same numerator.

  $\dfrac{3}{4}=\dfrac{6}{x}\\\\\dfrac{3\cdot2}{4\cdot2}=\dfrac{6}{x}\\\\\dfrac{6}{8}=\dfrac{6}{x}\ \Longrightarrow\ \boxed{x=8}$

The same thing happens if we multiply the equation by the inverse of either side.

  $\dfrac{3}{4}=\dfrac{6}{x}\ \Longrightarrow\ \left(\dfrac{4}{3}\right)\dfrac{3}{4}=\left(\dfrac{4}{3}\right)\dfrac{6}{x}\ \Longrightarrow\ 1=\dfrac{8}{x}\ \Longrightarrow\ \boxed{x=8}\\\\\textsf{ or ...}\\\\\dfrac{3}{4}=\dfrac{6}{x}\ \Longrightarrow\ \left(\dfrac{x}{6}\right)\dfrac{3}{4}=\left(\dfrac{x}{6}\right)\dfrac{6}{x}\ \Longrightarrow\ \dfrac{x}{8}=1\ \Longrightarrow\ \boxed{x=8}$

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graphical solution

If the equation is rewritten to a form that has a value of 0 at the solution, then the x-intercept of the graph will be the solution to the equation.

  3/4 = 6/x . . . . . . . . original equation

  6/x -3/4 = 0   ⇒   f(x) = 0

  f(x) = 6/x -3/4

The graph shows the solution to f(x) = 0 is x=8.