Answer with explanation:
The given expression is

→As, multiplication of real number follows Commutative property.
Which states that, if a and b are any two real numbers , then
a × b= b × a
The Expression equivalent to ,the above expression are

The answer is x=20. Hope this helps.
Answer:
It is 50 cm squared hxb/2=a
Step-by-step explanation:
We have,
If a quadratic equation with real coefficients has a discriminant of -36.
The general form of quadratic equation is :

The discriminant of this equation is : 
If D=0, it will have 1 real roots
If D>0, it will have 2 real roots
If D<0, it will have no real roots
We have,
D = -36 < 0, so, the quadratic equation will have no real roots.