(−1−5n+an2)−(7n−4n2+9)=12n2−12n−10If the given equation is true for all values of n where a is a constant, what is the value of a ?Choose 1 answer:(A) 8(B) 12(C) 16(D) 19
Q. (−1−5n+an2)−(7n−4n2+9)=12n2−12n−10If the given equation is true for all values of n where a is a constant, what is the value of a ?Choose 1 answer:(A) 8(B) 12(C) 16(D) 19
Distribute and Combine Terms: First, let's distribute the negative sign in the second set of parentheses and combine like terms on the left side of the equation.(−1−5n+an2)−(7n−4n2+9)=−1−5n+an2−7n+4n2−9
Combine Like Terms: Now, let's combine the like terms.−1−5n−7n+an2+4n2−9=−10−12n+(a+4)n2
Compare Coefficients: Next, we will compare the coefficients of the corresponding powers of n on both sides of the equation.Left side: −10−12n+(a+4)n2Right side: −10−12n+12n2
Set Coefficients Equal: For the equation to be true for all values of n, the coefficients of the corresponding powers of n must be equal on both sides.So, we set the coefficients of n2, n, and the constant terms equal to each other.(a+4)n2=12n2−12n=−12n−10=−10
Solve for a: Since the coefficients of n and the constant terms are already equal, we only need to solve for a from the equation involving n2 terms.a+4=12
Solve for a: Since the coefficients of n and the constant terms are already equal, we only need to solve for a from the equation involving n2 terms.a+4=12 Subtract 4 from both sides to solve for a.a=12−4a=8