Use factoring to solve each equation for real values of the
Use factoring to solve each equation for real values of the variable.
x3 + 4x2 - 21x = 0
8b3 - 10b2 + 3b -0
y4 - 50x2 + 49 = 0
Please solve and show your work, thankyou.
Solution
1) x^3 + 4x^2 - 21 x =0
x ( x^2 + 4x - 21 ) = 0
x ( x + 7) ( x - 3 ) = 0
2) 8b^3 - 10b^2 + 3b = 0
b ( 8b^2 - 10b + 3 ) = 0
b ( 2b-1 ) ( 4b - 3 ) = 0
3) y^4 - 50y^2 + 49 = 0
let y^2 = a
equation becomes
a^2 - 50 a + 49 = 0
(a-1)(a-49) = 0
a = y^2
(y^2 - 1) ( y^2 - 49 ) = 0
further factoring y^2-1 and y^2 - 49 by applying difference of squares formula
(y-1)(y+1)(y-7)(y+7) = 0
