Answer:
x= 7.87298334621 x=.12701665379
Step-by-step explanation:
This is in standard form so we have to factor this into
x^2-8x + 16 + 1 = 16
(x-4)^2 = 15
(x-4) = 
x-4= ± 3.87298334621
x-4 = 3.87298334621 x-4= -3.87298334621
x= 7.87298334621 x=.12701665379
the error is that they didnt add the exponets
Answer:
<em>Thus, the dimensions of the metal plate are 10 dm and 8 dm.</em>
Step-by-step explanation:
For a quadratic equation:

The sum of the roots is -b and the product is c. Note the leading coefficient is 1.
We know the perimeter of the rectangular metal plate is 36 dm and its area is 80 dm^2. Being L and W its dimensions, then:
P=2(L+W)=36
A=L.W=80
Note both formulas are closely related to the roots of the quadratic equation, we only need to adjust the data for the perimeter to be exactly the sum of L+W and not double of it.
Thus we use the semi perimeter instead as P/2=L+W=18
The quadratic equation is, then:

Factoring by finding two numbers that add up to 18 and have a product of 80:

The solutions to the equation are:
x=10, x=8
Thus, the dimensions of the metal plate are 10 dm and 8 dm.
Answer:
256 m and 3840 m²
Step-by-step explanation:
The 3 part of the ratio represents 48 m , then
48m ÷ 3 = 16 m ← value of 1 part of the ratio, so
5 parts = 5 × 16 m = 80 m
Then breadth = 48 m and length = 80 m
perimeter = 2l + 2b = 2(80) + 2(48) = 160 + 96 = 256 m
area = lb = 80 × 48 = 3840 m²