Which is the correct way to solve the given equation

Option 2. shows the correct way to use the quadratic formula to solve the given equation.

Step-by-step explanation:

Step 1:

For an equation of the form the solution is .

Here a is the coefficient of , b is the coefficient of x and c is the constant term.

can also be written as

Comparing with , we get that a is 1, b is -4 and c is -21.

To get the solution, we substitute the values of a, b, and c in .

Step 2:

Substituting the values, we get

This is option 2.

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it