x2 + 8x - 5 = 0 ∴ x2 + 8x + 16 = 21 ∴ (x + 4)2 = 21 ∴ x + 4 = ± √21 ∴ x = -4 ± √21
x - x2 - 9x + 14 = 0 ; whence, x2 + 8x = 14 , x2 + 8x + 16 = 30 , and x + 4 = ±√30 . Therefore, x = ±√30 - 4 .
x² + 8x - 48 = (x + 12)(x - 4) x² + 8x + 48 = (4+(√32)i)(4-(√32)i)
x2 - 2x - 15 = 0
x2 - 8x + 32 = 0 (assuming)you can factor or use the quadratic equation.I recommend the quadratic equation.
x2-8x=0 ( add 8x to both sides) x2 =8x (divide by x) x=8 ( x2divided by x equals x)
x2+8x+9 = -7 x2+8x+9+7 = 0 x2+8x+16 = 0 (x+4)(x+4) = 0 Therefore: x = -4 and also x = -4 (they both have equal roots)
no
I'll show work. X2-8x-4=0. X2-8x=4. X-8x=2. -7x=2. X=-(2/7).
x2 + 8x - 6 = 0 x2 + 8x + 16 = 22 (x + 4)2 = 22 x + 4 = ± √22 x = -4 ± √22
x2 + 8x - 5 = 0 ∴ x2 + 8x + 16 = 21 ∴ (x + 4)2 = 21 ∴ x + 4 = ± √21 ∴ x = -4 ± √21
y = x2 + 8x + 15 = (x + 3)(x + 5). When y = 0, one or other of the two factors must equal zero; that is, x = -3 or -5, when y = 0.
x2 + 8x - 9 = 0(x + 9) (x - 1) = 0(x + 9) = 0 . . . . . x = -9(x - 1) = 0 . . . . . x = 1
x2+8x+12 = 0 When factorized: (x+6)(x+2) = 0 Therefore: x = -6 or x = -2
The possible values for k are -2 and -14 because in order for the line to be tangent to the curve the discriminant must be equal to 0 as follows:- -2x-2 = x2-8x+7 => 6-x2-9 = 0 -14x-2 = x2-8x+7 => -6-x2-9 = 0 Discriminant: 62-4*-1*-9 = 0
x2+8x = -3x2+5 4x2+8x-5 = 0 (2x+5)(2x-1) = 0 x = -5/2 or x = 1/2
x - x2 - 9x + 14 = 0 ; whence, x2 + 8x = 14 , x2 + 8x + 16 = 30 , and x + 4 = ±√30 . Therefore, x = ±√30 - 4 .