Q. 3x2+ax−5=0In the given equation, a is a constant. If the equation has the solutions x=−5 and x=31, what is the value of a ?
Use Substitution Method: We will use the fact that if x=−5 and x=31 are solutions to the equation 3x2+ax−5=0, then they must satisfy the equation when substituted for x. First, let's substitute x=−5 into the equation. 3(−5)2+a(−5)−5=0
Calculate for x=−5: Calculate the square of −5 and multiply by 3. 3(25)+a(−5)−5=0 75−5a−5=0
Combine Like Terms: Combine like terms.70−5a=0
Solve for a: Add 5a to both sides to solve for a.70=5aDivide both sides by 5 to find the value of a. a=570 a=14
Calculate for x=31: Now, let's check the second solution x=31 by substituting it into the original equation to ensure it satisfies the equation with a=14.3(31)2+14(31)−5=0
Combine Like Terms: Calculate the square of 31 and multiply by 3. 3(91)+314−5=031+314−5=03(1+14)−5=0315−5=0
Final Solution: Simplify the fraction and subtract 5. 5−5=00=0 Since both solutions satisfy the equation with a=14, we have found the correct value of a.
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