2007-08-08 06:17:13 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
x + 1 = (2x - 4) ²
x + 1 = 4x² - 16x + 16
4x² - 17x + 15 = 0
x = [17 ± √(289 - 240)] / 8
x = [17 ± √49] / 8
x = [17 ± 7] / 8
x = 24 / 8 , x = 10 / 8
x = 3 , x = 5 / 4
2007-08-08 06:27:12 · answer #1 · answered by Como 7 · 3⤊ 0⤋
sqrt(x + 1) + 4 = 2x
Subtract 4 from both sides.
sqrt(x + 1) = 2x - 4
Square both sides.
x + 1 = 4x^2 - 16x + 16
Combine like terms.
4x^2 - 17x + 15 = 0
Solve as you would any quadratic equation. Then, you must complete the extra step of checking all of your solutions in the original equation. You will sometimes end up with an apparent solution that would only work if the square root function returned the negative value of the square root, which it does not.
2007-08-08 13:22:42 · answer #2 · answered by DavidK93 7 · 0⤊ 1⤋
sqrt(x + 1) + 4 = 2x
sqrt(x+1)=2x - 4
x+1=(2x-4)^2
x+1=4x^2-16x+16
4X^2-17x+15 = 0
find factors that multiply together to give 0
i.e. factorise
(x-3)(4x-5)=0
so x-3=0
and 4x-5=0
x=3
and x=5/4
2007-08-08 13:28:17 · answer #3 · answered by Anonymous · 0⤊ 2⤋
sqrt(x+1=2x-4
square both sides:
x+1=4x^2-16x+16.
4x^2-17x+15=0
4x^2-12x-5x+15=0
4x(x-3)-5(x+-3)=0
(x-3)(4x-5)=0
x=3,5/4ANS.
2007-08-08 13:59:12 · answer #4 · answered by renjth k 1 · 0⤊ 2⤋
sqrt(x+1=2x-4
square both sides:
x+1=4x^2-16x+16.
4x^2-17x+15=0
4x^2-12x-5x+15=0
4x(x-3)-5(x+-3)=0
(x-3)(4x-5)=0
x=3,5/4ANS.
2007-08-08 13:42:11 · answer #5 · answered by Anonymous · 0⤊ 2⤋