Question 20 of 25
1 point
after being rearranged and simplified, which equation cannot be solved using
the quadratic formula?
o
o
a. x2 - 6x- 7 = 2x
b. 2x2 – 3x+ 10 = 2x2 + 21
o
c. 5x2 – 3x + 10 = 2x2
o d. 2x - 4 = 2x2

B.

Step-by-step explanation:

A quadratic equation is of the form , where, a,b and c are any real numbers and .

The quadratic formula is given as:

Here, the value of can't be 0.

Now, the necessary condition to check if quadratic formula can be used in the given equations is to check the value of after rearranging them in the standard form.

Let us check each expression for the value of .

Option A:

Here, . So, we can use quadratic formula.

Option B:

Here, . So, we can't use quadratic formula.

Option C:

Here, . So, we can use quadratic formula.

Option D:

Here, . So, we can use quadratic formula.

So, only option B has . So, we can't use quadratic formula for option B.

step-by-step explanation:

here's what happens:

1) the graph of f   = x^2 is shifted 2 units to the right.

2) the resulting graph is reflected in the x-axis, so that the parabola now opens down.

3) this final result is transformed up by 5 units.