Question

Which number should each side of the equation 3/4x=9 be multiplied by to produce the equivalent equation of x = 12? −3/4 1/4 4/3 4

Answer 1

4/3

Explanation:

The equation should be multiplied by the reciprocal (multiplicative inverse) of the coefficient of x:

1/(3/4) = 4/3

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The product of any number and its multiplicative inverse is 1, the multiplicative identity element. 1 times x is x, so the equation becomes ...

(4/3)(3/4)x = (4/3)(9) . . . . multiply the given equation by 4/3

1x = 36/3 . . . . . simplify a bit

x = 12 . . . . . . . . simplify