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?◻
Given Quadratic Equation: We are given the quadratic equation3x2+ax−5=0 and its solutions x=−5 and x=31. To find the value of a, we can use the fact that if x is a solution to the equation, then substituting x into the equation should result in a true statement.
Substitute x=−5: First, let's substitute x=−5 into the equation:3(−5)2+a(−5)−5=0Calculate the square and multiply by 3:3(25)−5a−5=075−5a−5=0Combine like terms:70−5a=0
Solve for a using x=−5: Now, let's solve for a using the result from the substitution of x=−5: 70−5a=0 Add 5a to both sides: 70=5a Divide both sides by 5: a=570 a=14 This gives us a value for a based on the solution x=−5.
Verify using x=31: Next, we need to verify this value of a using the other solution x=31. Substitute x=31 into the original equation:3(31)2+a(31)−5=0Calculate the square and multiply by 3:3(91)+(31)a−5=031+(31)a−5=0Multiply the entire equation by 3 to clear the fractions:1+a−15=0Combine like terms:a−14=0
Solve for a using x=31: Now, let's solve for a using the result from the substitution of x=31: a−14=0 Add 14 to both sides: a=14 This confirms that the value of a is indeed 14, as it satisfies the equation with both given solutions x=−5 and x=31.
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