Answer:
see below
Step-by-step explanation:

and the other

Answer:
This ans is easily solved by using algebraic identities a²- b² = (a+b) (a-b)
Step-by-step explanation:
1. convert into Identity
2. solve quadratic equation that formed.
IF the estimates are 100% accurate, then the maximum volume of concrete is the product of the maximum dimensions, namely
Vmax=18.32*12.22*0.55=123.13 m^3
and the minimum volume of concrete is the product of the minimum dimensions
Vmin=18.28*12.18*0.45=100.19 m^3
the uncertainty is therefore 123.13-100.19=22.94 m^3
On the practical side, to this uncertainty must be added to
- squareness of the formwork
- evenness of the surface of the crushed stones on which the foundation sits on
- excess of concrete delivered by the truck
- volume of air bubbles trapped in the the concrete, ...
Answer:
The side lengths cannot belong to a right triangle.
Step-by-step explanation:
This is a simple case of Pythagorean proof. If this triangle was a right triangle, 20^2 + 21^2 = 28^2. However, this is not the case. 20^2 + 21^2 = 841, which square root is 29.
If you forgot, the Pythagoren Theorem is: a^2 + b^2 = c^2.
Hope this helps!
Sum 81 to both sides to get

Divide both sides by 4 to get

Consider the square root of both sides. Note that this requires the
sign, since
implies
, but also
. So, the solutions are
