Question

Solve : 7y = -3y² - 4 

Answer 1

(1) 7y = -3y² -4
∴ 3y² + 7y + 4 = 0
Here a = 3, b = 7, c = 4
∴ y = `(-b +- sqrt(b^2 - 4ac))/2a`

      =`(-7+-sqrt(449-48))/6`

      =`(-7+-sqrt(1))/6`

Alternate Method
3y² + 3y + 4y + 4 = 0
∴ 3y(y + 1) + 4(y + 1) = 0
        ∴ (3y + 4) (y + 1) = 0
∴ y = -1 or y = −`4/3`

∴ y = `(-7+1)/6 or y = (−7-1)/6`
∴ y = -1 or y = -` 8/6= -4/3`