Solve the following equations by factorisation.
Q1) 36x^2 + 3x - 5 = 0
Q2) x^2 - 14x - 176 = 0
Q3) 25x^2 - 414x -187 = 0
No calculators are allowed.
Duration 8 minutes.
Show your working clearly and systematically.
2007-07-14 04:02:34 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Q1)
36x^2 + 3x - 5 = 0
36x^2 - 12x + 15x - 5 =0
12x(3x-1)+5(3x-1)=0
(12x+5)(3x-1)=0
x=1/3
or
x=-5/12
Q2)
x^2 - 14x - 176 = 0
x^2 + 8x - 22x - 176 =0
x(x+8)-22(x+8)=0
(x-22)(x+8)=0
x=22
or
x=-8
Q3)
25x^2 - 414x -187 = 0
25x^2 + 11x - 425x - 187 = 0
x(25x+11)-17(25x+11)=0
(x-17)(25x+11)=0
x=17
or
x=-11/25
2007-07-14 04:26:52 · answer #1 · answered by fofo m 3 · 0⤊ 0⤋
Q1) 36x^2 + 3x - 5 = 0
(3x-1)(12x+5)
x = 1/3 or -5/12
Q2) x^2 - 14x - 176 = 0
= (x-22)(x+8)
x=22 or -8
Q3) 25x^2 - 414x -187 = 0
(x+17)(25x-11)
x = -17 or 11/25
2007-07-14 04:29:16 · answer #2 · answered by ironduke8159 7 · 0⤊ 0⤋
Q1) 36x^2 + 3x - 5 = 0
(3x - 1)(12x + 5) = 0
x = 1/3 or x = -5/12
Q2) 25x^2 - 414x - 187 = 0
(x - 17)(25x + 11) = 0
x = 17 or x = -11/25
Q3) x^2 - 14x - 176 = 0
(x - 22)(x + 8) = 0
x = 22 or x = -8
2007-07-14 04:09:48 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Question 1
(12x + 5) (3x - 1) = 0
x = - 5 / 12 , x = 1 / 3
Question 2
(x - 22) (x + 8) = 0
x = 22 , x = - 8
Question 3
(25 x + 11 ) (x - 17) = 0
x = - 11 / 25 , x = 17
2007-07-14 06:52:36 · answer #4 · answered by Como 7 · 0⤊ 0⤋
36^2+3x-5=0
(12x+5)(3x-1)=0
12x+5=0 3x-1=0
12x=-5 3x=1
x=-5/12 x=1/3
x^2-14x-176=0
(x+8)(x-22)=0
x+8=0 x-22=0
x=-8 x=22
25x^2-414x-187=0
(25x+11)(x-17)=0
25x+11=0 x-17=0
25x=-11 x=17
x=-11/25
2007-07-14 04:26:33 · answer #5 · answered by bigpapa_joemama 1 · 0⤊ 0⤋
Q1) 36x^2 + 3x - 5 = 0
Here it goes:
36x^2 + 3x - 5 = 0
..........3x can be written as 15x -12x...so
36x^2 + (15x - 12x) - 5=0
(36x^2 + 15x) - (12x + 5) = 0
3x(12x +5) - (12x + 5) = 0
(3x-1)(12x+5) = 0
now 3x-1 = 0 yields
3x = 1
x =1/3
(12x+5) = 0 yields..
12x = -5
x =-5/12
Hence there are two solutions x = 1/3, -5/12
Hope the other can also be solved like this.
2007-07-14 04:18:42 · answer #6 · answered by Beurself 2 · 0⤊ 0⤋
we just did these at the end of last semester...you can either use "completing the square" method or the quadratic formula...if you know either one, the problems become fairly simple.
2007-07-14 04:24:25 · answer #7 · answered by b_waks 2 · 0⤊ 0⤋
how do u check tat someone dsnt use d calculator... u r tooooo brainy... pls cool bro...! tat vas jus 4 fun.....!
2007-07-14 05:26:58 · answer #8 · answered by Aravinthan J 2 · 0⤊ 0⤋
OMG! easy?!?!?!?!?!ar u a genius or sumthing
2007-07-14 04:10:47 · answer #9 · answered by Brian 2 · 0⤊ 1⤋