-3x^2 + 12x
2007-10-15 18:45:19 · 7 answers · asked by Mags 1 in Science & Mathematics ➔ Mathematics
-3x^2+12x
-3(x^2-4x)
-3(x^2-4x+4)+12
2007-10-15 18:49:27 · answer #1 · answered by ptolemy862000 4 · 1⤊ 1⤋
1. Divide by -3: x^2 - 4x
2. Since your square is equal to (x + b) ^2, it expands to x^2 + 2 * b * x + b^2. So, -4x = 2bx. or -2 = b
3. Using b = -2, fill in the equation: (x - 2)^2 = x^2 - 4x + 4
4. Multiply the -3 back in: -3x^2 + 12x - 12
2007-10-15 18:53:47 · answer #2 · answered by MistWing 4 · 0⤊ 0⤋
-3X^2+12X=-3[(X^2-4X)] take out common factor of -3
=-3[(x-2)^2-4] complete the square on innermost brackets
=-3(x-2)^2+12 remove the outermost brackets
finished.
It is a good idea to remove brackets in the final line and check that we go back to the original expression.
2007-10-15 18:58:42 · answer #3 · answered by Neil 2 · 0⤊ 0⤋
-3 (x^2 + 4x)
-3 (x^2 - 4x + (4/2)^2) - (-3)(4/2)^2
-3 (x^2 - 4x + 4) + 12
-3 (x - 2)^2 + 12
check:
-3 (x^2 - 4x + 4) - 12
-3x + 12x - 12 + 12
-3x + 12x
2007-10-15 18:57:29 · answer #4 · answered by 7 · 0⤊ 0⤋
-3x^2 + 12x
= - 3(x^2 - 4x + 4) + 12
= - 3(x - 2)^2 + 12
2007-10-15 18:50:07 · answer #5 · answered by Madhukar 7 · 1⤊ 1⤋
( - 3 ) ( x ² - 4x + 4 - 4 )
( - 3 ) ( x ² - 4x + 4) + 12
( - 3 ) ( x - 2) ² + 12
2007-10-16 03:47:35 · answer #6 · answered by Como 7 · 0⤊ 0⤋
-3x^2 + 12x
3(4 - x^2)
3(2 -x)(2 + x)
2007-10-15 18:48:31 · answer #7 · answered by ib 4 · 1⤊ 0⤋