Question

Write the quadratic equation in general form. What is the value of b 2 - 4ac?

1 = 2x 2 + 7x

40
41
57

Answer 1

0=ax^2+bx+c
we got
1=2x^2+7x
minus 1 both sides
0=2x^2+7x-1
a=2
b=7
c=-1

b^2-4ac=
7^2-4(2)(-1)=
49+8=
57

Answer 2

The value of b² - 4ac is 57

Explanation:

To find the value of b² - 4ac in the equation;

1 = 2x² + 7x

We need to first rearrange the equation

2x² + 7x - 1 = 0 -----------------------------------------------------------------(1)

The general form of quadratic equation is;

ax² + bx + c = 0 ---------------------------------------------------------------(2)

Comparing equation (1) and equation (2)

a =2 b=7 and c= -1

We are ask to find b² - 4ac

Substitute the values into b² - 4ac

b² - 4ac = 7² -(4)(2)(-1)

=49 +8

=57

Therefore, the value of b² - 4ac is 57