Question

Solve the quadratic equation by using a graphic approach. Round your answer to the hundredths place,

x² - 2x -
40
a. x= 3.24 or x = -1.24
b. x = 2.73 or x = -0.73
c. x = 4.24 or x = -0.24
d. x = 5.24or x = -1.24

Pls help and explain I’m having a hard time understanding the lesson

Answer 1

Explanation:

Well, I really don’t like graphic approaches in math, so hear ya go a formula:

Although there are easier ways that work for some quadratics, but this formula works for them all. (It is atached, have a look)

So,

( -(-2)+- square root of ((-2)^2-4(1)(-40)) ) / 2(1)

Note that for a hear I use one, since there is nothing in front of x.

( 2 + (12.8) ) / 2 < with plus

( 2 -(12.8) ) / 2 < with minus

X = 7.4

Or

X = -5.4

(Quad equations have 2 answers)