9514 1404 393
Answer:
x = 3(y -1)
Step-by-step explanation:
In this, and any, "solve for ..." situation, you want to first take a look at where the variable of interest is in the equation, and what has been done to it.
Here, x is on the right side (only). It has these operations done to it:
You solve for x by undoing these operations, in reverse order. As always, with any equation, you do the same thing to both sides of the equation.
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First, we will undo "add 1". We do that by adding the opposite of 1.
y -1 = 1/3x +1 -1 . . . . . -1 added (to both sides)
y -1 = 1/3x . . . . . . . . . simplify
To undo the "multiply by 1/3", we can multiply by the "multiplicative inverse" (reciprocal) of 1/3. That is, we want to multiply by 3.
3(y -1) = 3(1/3x) . . . . . multiply (both sides) by 3
3(y -1) = x . . . . . . . . . simplify
We can leave it like this.
x = 3(y -1)
Or, we can eliminate parentheses using the distributive property .
x = 3y -3
These are completely equivalent equations with x as the subject.
