Question

Complete the following activity to solve the given quadratic equation by formula method.

2x² + 13x + 15 = 0

Activity: 2x² + 13x + 15 = 0

a = (______), b = 13, c = 15

b² – 4ac = (13)² – 4 × 2 × (______)

= 169 – 120

b² – 4ac = 49

x = `(-"b" +- sqrt("b"^2 - 4"ac"))/(2"a")`

x = `(- ("______") +- sqrt(49))/4` 

x = `(-13 +- ("______"))/4`

x = `(-6)/4` or x = `(-20)/4`

x = (______) or x = (______)

Answer 1

2x² + 13x + 15 = 0

a = 2, b = 13, c = 15

b² – 4ac = (13)² – 4 × 2 × 15

= 169 – 120

b² – 4ac = 49

x = `(-"b" +- sqrt("b"^2 - 4"ac"))/(2"a")`

x = `(- (13) +- sqrt(49))/4` 

x = `(-13 +- 7)/4`

x = `(-13 + 7)/4` or x = `(-13 - 7)/4`

x = `(-6)/4` or x = `(-20)/4`

x = `(-3)/2` or x = − 5