How do you solve this quadratic equation 2x^2- 10+ 7=0?

2 Answers
Jun 3, 2018

x=+-1/2sqrt6

Explanation:

2x^2-10+7=0
Add 3 on both sides to move the constants to the right side:
2x^2-10+7+3=0+3
2x^2=3
Divide both sides with 2:
x^2=3/2
x=+-sqrt(3/2)=+-1/2sqrt3sqrt2=+-1/2sqrt6
(if we multiply the right side with sqrt2/sqrt2)

Jun 3, 2018

x = (5 pm sqrt(11))/2

Explanation:

if 2x^2 -10x + 7 = 0

You can use the quadratic formula:

ax^2 +bx + c = 0

=> x = ( -bpmsqrt(b^2 - 4ac) ) / (2a)

In this case a = 2 , b = -10 , c = 7

=> x =( - (-10 ) pm sqrt( (-10)^2 - (4 * 2 * 7 ) ) ) / ( 2 * 2)

=> x = (10 pm sqrt(44)) / 4

=> x= (10 pm 2sqrt(11) )/ 4

color(red)(=> x = (5 pm sqrt(11))/2