9514 1404 393
Answer:
x = ±√((d -c)/a)
Step-by-step explanation:
The usual "solve for ..." approach works fine in this case.
ax^2 +c = d
ax^2 = d - c . . . . . subtract c
x^2 = (d -c)/a . . . . divide by a
x = ±√((d -c)/a) . . . take the square root
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When there are numbers, a graphical solution could work. It depends on whether an exact or approximate solution is required.
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<em>Comment on "solve for ..."</em>
When solving an equation for a specific variable, it is worthwhile to consider the Order of Operations. Look at what has been done to the variable, then undo those operations in reverse order. Here, the variable has been squared, the product multiplied by 'a', that product added to c. So, the "undo" consists of subtracting 'c', dividing by 'a', and taking the square root.
