The rate that you are walking at is 100 meters per minute. In two kilometres there are 2000 meters. It takes 10 min to walk one kilometre. Therefore the answer is 20 minutes. Just divide 2000 by 100 to get the time
First what you need to do is 4.2 x 0.6 and that will be you answer.
Can you take a clearer pic?
it’s kinda dark & blurry
1. x^2 + 13x + 36 = 0
using powerful & time-sparing quadratic formula :
delta = 13^2 - 4*1*36 = 25 = 5^2
x1 and x2 = (-13 -/+ 5)/2 = -9 and -4
x^2 + 13x + 36 = (x+9)(x+4)
2. other way : complete the square
b^2 + 12b + 32 = b^2 + 2*6b + 6^2 - 6^2 + 32
b^2 + 12b + 32 = (b+6)^2 - 4
b^2 + 12b + 32 = (b+6-2)(b+6+2) = (b+4)(b+8)
3. other way : -4 "ovious" solution : (-4)^2 - (-4) -20 = 0
so the other is : -4 . a2 = -20/1 ---> a2 = 5
a^2 - a - 20 = (a-5)(a+4)
