Step-by-step explanation:
b^2-4b+3=0
b²-3x-b+3=0
b(b-3)-1(b-3)=0
(b-3)(b-1)=0
either
b=3 or b=1
.
2n^2 + 7 = -4n + 5
2n²+4n+7-5=0
2n²+4n+2=0
2(n²+2n+1)=0
(n+1)²=0/2
:.n=-1
.
x - 3x^2 = 5+ 2x - x^2
0=5+ 2x - x^2-x +3x^2
0=5+x+2x²
2x²+x+5=0
comparing above equation with ax²+bx +c we get
a=2
b=1
c=5
x={-b±√(b²-4ac)}/2a ={-1±√(1²-4×2×5)}/2×1
={-1±√-39}/2
Answer:
Step-by-step explanation:
a) False. There are three factor pairs for 36:
1×36
2×18
3×12
4×9
6×6
b) True.
18 = 2×3²
Odd divisors of 18: 1, 3, 9
1+3+9 = 13
c) False
100 = 2×5²
25 = 5²
Greatest common divisor = 25
Your answer should be D. 3
Answer:
Step-by-step explanation:
- speed = distance / time
- time = distance / speed
a)
i)
<u>Time taken at the first part:</u>
ii)
<u>Time taken at the second part:</u>
- (190 - 105) / (x + 12) =
- 85/(x + 12)
b)
<u>If time is 3 hours and 15 minutes = 3 1/4 hours = 13/4 hours, the equation is:</u>
- 105/x + 85/(x + 12) = 13/4
- 4(x + 12)*105 + 4(85x) = 13x(x + 12)
- 13x² - 604x - 5040 = 0
c)
<u>Solve the equation:</u>
- 13x² - 604x - 5040 = 0
- x = [604 ± √((-604)² + 4*13*5040) ]/26 =
- [604 ± √626896]/26 =
- [604 ± 791.77]/26
- x = (604 + 791.77)/26 = 53.68 km/h (taking positive root only)
d)
- 105/x = 105/53.68 h = 1.956 h = 1 h 0.956*60 min = 1 h 57 min (rounded)
- 85/(53.68 + 12) = 85/65.68 = 1.294 h = 1 h 0.294*60 min = 1 h 18 min (rounded)
