Peta attempted to solve the following equation. explain peta's error.
x (x - 5) = 20
x = 20 and x - 5 = 20
x = 20 and x = 25

see explanation

Step-by-step explanation:

The error is in equating x(x - 5) = 20

and assuming x = 20 , x - 5 = 20

The correct approach is to rearrange the equation into standard form by subtracting 20 from both sides and equating to zero, that is

x(x - 5) - 20 = 0

x² - 5x - 20 = 0 ← in standard form

Then solve using the quadratic formula or completing the square

answer

d. 10

explanation

the distance from point y to wx is the height of the triangle.

using pythagoras theorem,

group similar terms to get,

this implies that,

take positive square root of both sides to get,

this implies that,

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.