Question

Use the quadratic formula s to solve 2y^2-6y-8=0

{-4,-1}

{4,-1}

{-4,1}

{4,1}

Answer 1

{4, - 1}

Explanation:

Given

2y² - 6y - 8 = 0 ← in standard form

with a = 2, b = - 6, c = - 8

Using the quadratic formula to solve for y

y = ( - (- 6) ±
`√((-6)^2-(4(2)(-8))` ) / (2 × 2)

= ( 6 ±
`√(36+64)` ) / 4

= ( 6 ±
`√(100)` ) / 4

= ( 6 ± 10 ) / 4

x =
`(6+10)/(4)` =
`(16)/(4)` = 4

OR

x =
`(6-10)/(4)` =
`(-4)/(4)` = - 1

Solution is { 4, - 1 }