Problem: what is 3x^2+24x+48=0?
3x^2 + 24x + 48 = 0
Factor.
(3x + 12)(x + 4) = 0
Set each factor to 0 and solve for x.
(3x + 12) = 0
3x = -12
x = -4
(x + 4) = 0
x = -4
3x^2 + 24x + 48 = 0
3(-4)^2 + 24(-4) + 48 = 0
3(16) - 96 + 48 = 0
48 - 96 + 48 = 0
Note:48 + 48 = 96
96 - 96 = 0
Also, note that x = 4 is NOT a solution.
3x^2 + 24x + 48
3(4)^2 + 24(4) + 48
3(16) + 96 + 48
48 + 96 + 48
96 + 96 = 192
The only answer is: x = -4