That would be a quadratic equation which can be factored out to (x + 12)(x - 4) = 0, telling us that x is equal to -12 or 4. If you're having a hard time finding the factors, another way to find the answers is to complete the square and solve for x:
x2 + 8x - 48 = 0
x2 + 8x + 16 = 64
(x + 4)2 = 64
x + 4 = √64
x = -4 ± 8
x ∈ {-12, 4}
x2 + 7x = 2x2 + 6 x2 - 2x2 + 7x = 6 -x2 +7x - 6 = 0 or alternatively x2 - 7x + 6 = 0
x2 + 49 = 0 ∴ x2 = -49 ∴ x = 7i
-2
No.
168
x2 plus 3x plus 3 is equals to 0 can be solved by getting the roots.
x2 + 7x = 2x2 + 6 x2 - 2x2 + 7x = 6 -x2 +7x - 6 = 0 or alternatively x2 - 7x + 6 = 0
no
x2 + 49 = 0 ∴ x2 = -49 ∴ x = 7i
-2
No.
168
x2 + 10x = 0 x2 + 10x + 25 = 25 (x + 5)2 = 25 x + 5 = +-5 x1 = 0 x2 =10
If: y = x2+20x+100 and x2-20x+100 Then: x2+20x+100 = x2-20x+100 So: 40x = 0 => x = 0 When x = 0 then y = 100 Therefore point of intersection: (0, 100)
x2-5-4x2+3x = 0 -3x2+3x-5 = 0 or as 3x2-3x+5 = 0
x = -3.27 or -6.73
x2 + 4x + 3 = 0 (x + 1)(x + 3) = 0 x ∈ {-3, -1}