2007-05-02 12:56:42 · 9 answers · asked by hello 1 in Science & Mathematics ➔ Mathematics
(t - 2)(8t + 21)
Find factors of 8*42 = 336 that differ by 5. They are 21 & 16.
8t^2 + 5t - 42
= 8t^2 - 16t + 21t - 42
= 8t(t - 2) + 21(t - 2)
= (t - 2)(8t + 21)
2007-05-02 12:59:18 · answer #1 · answered by Anonymous · 0⤊ 0⤋
8t^2 + 5t - 42 (find the multiples of the fist and the last items)
8t 21
t -2
to check, multiply the crossed items and you have to get the second item of the equation.
8t x -2 = -16 t
t x 21 = 21 t
- 16 t + 21 t = 5t
then the result is;
(8t+21) x (t-2)
2007-05-02 20:08:02 · answer #2 · answered by nelaq 4 · 0⤊ 0⤋
(8t^2) + 5t - 42
t(8t + 5) - 42
[8t + 5] (t-42)
where 8t + 5 = 0
t = - 5/8
or
where t - 42 = 0
t = 42
righ'??...whats factorise again?
2007-05-02 20:01:37 · answer #3 · answered by ? 3 · 0⤊ 0⤋
Use the quadratic formula
(-5 +/- sqrt(25 + 1344))/2
(-5 +/- sqrt(1369))/2
(-5 +/- 37)/2
-42/2 or 32/2
-21 or 16
2007-05-02 20:01:08 · answer #4 · answered by TychaBrahe 7 · 0⤊ 0⤋
8t^2+5t-42
8t^2-16t+21t-42
(8t+21)(t-2)
2007-05-03 01:38:54 · answer #5 · answered by bootis32 6 · 0⤊ 0⤋
(8t + 21) (t - 2)
2007-05-02 20:00:29 · answer #6 · answered by romeo_1595 2 · 0⤊ 0⤋
69t-42
2007-05-02 19:59:23 · answer #7 · answered by Mark C 1 · 0⤊ 2⤋
I don't think it's factorable.
2007-05-02 20:01:40 · answer #8 · answered by ay3e 2 · 0⤊ 1⤋
no
2007-05-02 20:14:16 · answer #9 · answered by ? 2 · 0⤊ 0⤋