Use the quadratic formula to solve the equation -x^2 + 7x = 8
Thank you so much both of you! Do you think you could help me out with any more?
To solve the equation -x^2 + 7x = 8 using the quadratic formula, we first need to rewrite the equation in standard quadratic form, which is ax^2 + bx + c = 0.
In this case, we have -x^2 + 7x - 8 = 0. By comparing this equation to the standard form, we see that a = -1, b = 7, and c = -8.
Now, let's plug these values into the quadratic formula:
x = (-b ± √(b^2 - 4ac))/(2a)
Replacing the variables with the corresponding values, we have:
x = (-(7) ± √((7)^2 - 4(-1)(-8)))/(2(-1))
Simplifying the formula further, we get:
x = (-7 ± √(49 - 32))/(-2)
x = (-7 ± √17)/(-2)
Using this formula, we can find two possible solutions for x:
x = (-7 + √17)/(-2) or x = (-7 - √17)/(-2)
Hence, the solutions to the equation -x^2 + 7x = 8 using the quadratic formula are (-7 + √17)/(-2) and (-7 - √17)/(-2).
x^2 - 7 x = -8
or
1 x^2 - 7 x + 8 = 0
x = [ 7 +/- sqrt(49 - 32) ] /2
x = [ 7 +/- sqrt(17) ]/2
x = 1.44 or 5.56
First set into standard form:
x^2-7x+8 = 0
the discriminant is b^2-4ac = 49-32=17
Now you try and plug that into the formula. After all, I know how to do it -- you need the practice