x= (9+-sqrt(81+4*4*9))/8
x= 1/2 +- 15/8
What are the solutions of the quadratic equation?
4x^2 - 9x - 9 = 0
3 answers
Thank you!
Substitute the values a = 4 , b = - 9 , c = - 9 into the quadratic formula
x1/2 = [ - b +OR- sqroot( b ^ 2 - 4 a c ) ] / 2 a
x1/2 = [ - ( - 9 ) +OR- sqroot( ( - 9 ) ^ 2 - 4 * 4 * ( - 9 ) ) ] / 2 * 4
x1/2 = [ 9 +OR- sqroot( 81 - 4 * ( - 36) ) ] / 8
x1/2 = [ 9 +OR- sqrt ( 81 + 144 )] / 8
x1/2 = [ 9 +OR- sqrt ( 255 )] / 8
x1/2 = ( 9 +OR- 15 ) / 8
x1 = ( 9 + 15 ) / 8 = 24 / 8 = 3
x2 = ( 9 - 15 ) / 8 = - 6 / 8 = - 3 * 2 / ( 4 * 2 ) = - 3 / 4
The solutions are :
x = - 3 / 4 and x = 3
x1/2 = [ - b +OR- sqroot( b ^ 2 - 4 a c ) ] / 2 a
x1/2 = [ - ( - 9 ) +OR- sqroot( ( - 9 ) ^ 2 - 4 * 4 * ( - 9 ) ) ] / 2 * 4
x1/2 = [ 9 +OR- sqroot( 81 - 4 * ( - 36) ) ] / 8
x1/2 = [ 9 +OR- sqrt ( 81 + 144 )] / 8
x1/2 = [ 9 +OR- sqrt ( 255 )] / 8
x1/2 = ( 9 +OR- 15 ) / 8
x1 = ( 9 + 15 ) / 8 = 24 / 8 = 3
x2 = ( 9 - 15 ) / 8 = - 6 / 8 = - 3 * 2 / ( 4 * 2 ) = - 3 / 4
The solutions are :
x = - 3 / 4 and x = 3
1 answer