f(x)=9÷4x-15 for x=4
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9/4x -15 for x=4
To find this answer you must plug the 4 everywhere the x is located.
(9/4)(4) -15
Multiply 9/4 by 4
(9/4) x 4 = 9
Now we take our 9 answer and add it to -15.
9-15 = -6
The answer is -6
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For the other equation, you also must plug in 3 where ever x is located in the equation.
5/3x -3/5
(5/3)(3) -3/5
Multiply 5/3 and 3
(5/3) x 3 = 5
Take that answer of 5 and add -3/5
5- (3/5) =4 2/5
The answer to this equation would be 4 2/5 or 4.4