2007-05-25 05:33:38 · 8 answers · asked by laura_minerusmc 1 in Science & Mathematics ➔ Mathematics
5
FOIL each polynomial:
(3x^2-ax-6x+2a)(x-7)
3x^3-21x^2-ax^2+7ax-6x^2+42x+2ax-14a
You could just do it from here easily because the only term without x in it in the answer is -70, and the only term without x in it in this polynomial is -14a, so -70/-14=5=a
If you wanted to keep going to check your answer then put like terms together:
3x^3-(27+a)x^2+(9a+42)x-14a
Solve each coefficient for its corrisponding solution:
-(27+a) = -32
(9a+42) = 87
-14a = -70
Every solution gives a = 5
2007-05-25 05:39:34 · answer #1 · answered by ooorah 6 · 0⤊ 0⤋
5
2007-05-25 06:00:07 · answer #2 · answered by rick y 3 · 0⤊ 0⤋
ax 2 x 7 = 70
14 a = 70 divide by 14
a = 5
2007-05-25 05:37:19 · answer #3 · answered by muhamed a 4 · 0⤊ 0⤋
a=5
2007-05-25 05:36:27 · answer #4 · answered by jkicker 3 · 0⤊ 0⤋
a = 5.
I really hate dividing polynomials, but if you divide 3x3-32x2+87x-70 by x-2 you get 3x^2 -26x + 35. If you divide that by x-7 you get 3x - 5
2007-05-25 05:39:15 · answer #5 · answered by TychaBrahe 7 · 0⤊ 0⤋
(3x-a)(x-2)(x-7)
(3x^2-6x-ax+2a)(x-7)
3x^3 - 21x^2 -6x^2 + 42x -ax^2 +7ax + 2ax - 14a
3x^3 -27x^2 - ax^2 + 42x + 9ax - 14a
3x^3 -(27+a)x^2 +(42+9a)x - 14a
27 + a = 32 ==> a = 5
42 + 9a = 87 ==> a = 5
14a = 70 ==> a = 5
2007-05-25 05:45:26 · answer #6 · answered by T 5 · 0⤊ 0⤋
Equate the absolute term in each side
(-a )(-2)(-7)= -70
So a = 5
2007-05-25 05:43:22 · answer #7 · answered by a_ebnlhaitham 6 · 0⤊ 0⤋
Do the Xs on the right signify variables or are they multiplication signs?
2007-05-25 05:45:20 · answer #8 · answered by Steve 6 · 0⤊ 0⤋