Questions on Algebra: Quadratic Equation answered by real tutors!

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Question 150983: I don't have a book. This is a summer assignment.
Solve the following eqation x^2 + 10x - 16 = 0 : I don't have a book. This is a summer assignment.
Solve the following eqation x^2 + 10x - 16 = 0
Answer by jim_thompson5910(8302) About Me  (Show Source):
You can put this solution on YOUR website!

x^2+10x-16=0 Start with the given equation.


Notice we have a quadratic equation in the form of ax^2+bx+c where a=1, b=10, and c=-16


Let's use the quadratic formula to solve for x


x = (-b +- sqrt( b^2-4ac ))/(2a) Start with the quadratic formula


x = (-(10) +- sqrt( (10)^2-4(1)(-16) ))/(2(1)) Plug in a=1, b=10, and c=-16


x = (-10 +- sqrt( 100-4(1)(-16) ))/(2(1)) Square 10 to get 100.


x = (-10 +- sqrt( 100--64 ))/(2(1)) Multiply 4(1)(-16) to get -64


x = (-10 +- sqrt( 100+64 ))/(2(1)) Rewrite sqrt(100--64) as sqrt(100+64)


x = (-10 +- sqrt( 164 ))/(2(1)) Add 100 to 64 to get 164


x = (-10 +- sqrt( 164 ))/(2) Multiply 2 and 1 to get 2.


x = (-10 +- 2*sqrt(41))/(2) Simplify the square root (note: If you need help with simplifying square roots, check out this solver)


x = (-10)/(2) +- (2*sqrt(41))/(2) Break up the fraction.


x = -5 +- sqrt(41) Reduce.


x = -5+sqrt(41) or x = -5-sqrt(41) Break up the expression.


So our answers are x = -5+sqrt(41) or x = -5-sqrt(41)


which approximate to x=1.403 or x=-11.403