A crane has a cable with a breaking strain of 6400kg measured to 2 significant figures it is used to lift crates which weigh 90kg measured to the nearest 10kg what is the greatest number of crates that can safely be lifted at one time without breaking the cable some working must be shown

100/2=50

lower bound of 6400kg = 6350kg

10/2=5  

upper bound of 90kg = 95kg

6350kg/95kg=66kg

Step-by-step explanation:

this is right

company a

step-by-step explanation:

using the linear regression models , it is found that company a   pays about $14 more. but using the same regression (linear) company b pays about $10 more.

so company a pays more than b

let's call the solutions x₁ = (5 - 2√7)/3 and x₂ = (5 + 2√7)/3

then the equation is (x-x₁)(x-x₂) = 0

if you fill that in you get a lot of numbers which you can recognize as ax²+bx+c=0.

step-by-step explanation:

you can see that a=1 (there is just an x²)

b = (-5 -2√7 + 2√7 - 5)/3 = -10/3

c = -2√7)/3 ) * (-5+2√7)/3) = -1/3

so your answer is 3x^2 – 10x – 1 = 0