Find the Leading Coefficient in -x² + 7x - 9: Identifying Value of a

Question

What is the value ofl coeficiente a a in the equation?

x2+7x9 -x^2+7x-9

Video Solution

Solution Steps

00:00 Find the coefficient A in the equation
00:03 We'll use the formula for representing a quadratic equation
00:11 We can see that coefficient A is of X squared
00:18 Let's compare the formula to our equation and find A
00:21 Every number is essentially multiplied by 1
00:24 And this is the solution to the question

Step-by-Step Solution

The quadratic equation in the problem is already arranged (meaning all terms are on one side and 0 on the other side), so let's proceed to answer the question asked:

The question asked in the problem - What is the value of the coefficienta a in the equation?

Let's recall the definitions of coefficients in solving quadratic equations and the roots formula:

The rule states that the roots of an equation of the form:

ax2+bx+c=0 ax^2+bx+c=0 are:

x1,2=b±b24ac2a x_{1,2}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}

That is the coefficient a a is the coefficient of the quadratic term (meaning the term with the second power)- x2 x^2 Let's examine the equation in the problem:

x2+7x9=0 -x^2+7x-9 =0

Let's remember that the minus sign before the quadratic term means multiplication by: 1 -1 , therefore- we can write the equation as:

1x2+7x9=0 -1\cdot x^2+7x-9 =0

meaning- the number that multiplies the x2 x^2 , is 1 -1 therefore we identify that the coefficient of the quadratic term is the number 1 -1 ,

Therefore the correct answer is A.

Answer

-1