SOLUTION: Solve by completing the square. (When I do this, I get a LOT of fractions. I feel like I'm missing something big in this problem.) 8x^2+10x=3

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Question 1127312: Solve by completing the square.
(When I do this, I get a LOT of fractions. I feel like I'm missing something big in this problem.)
8x^2+10x=3

Found 3 solutions by josgarithmetic, MathLover1, greenestamps:
Answer by josgarithmetic(39620)   (Show Source): You can put this solution on YOUR website!


or just start from original equation,








,




OR

.

Answer by MathLover1(20850)   (Show Source): You can put this solution on YOUR website!







coefficients: ,

find
->->








Answer by greenestamps(13200)   (Show Source): You can put this solution on YOUR website!


You are likely to get fractions when completing the square, except in "nice" problems....



Factor out the leading coefficient:



Take half the coefficient of the x term (5/8), square it (25/64), and add 25/64 in the parentheses on the left, to complete the square. Note that you added 8*25/64 = 25/8 on the left side of the equation, so you need to add 25/8 on the right to keep the equation balanced.

(Note that the only time you will NOT get fractions in the process of completing the square is when half the coefficient of x is an integer.)



Write the expression in parentheses as the square of a binomial, and simplify the expression on the right:



Divide by 8 to get the squared binomial by itself:



Take the square root of both sides, getting both positive and negative roots on the right:

OR

Solve the two equations to find the two roots of the original equation:

OR

The two roots of the equation are 1/4 and -3/2.

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