Question

What are the approximate solutions of 2x² – x + 10 = 0?

a) -2, 2.5
B) -1.97, 2.47
C) -2.5, 2
D) no solution

Answer 1

Metjod 1, try each choice in the equation.
a) Does -2 work?
Plug in -2 for x in left side of equation and evaluate left side.
2(-2)^2 -(-2) + 10 =
8 + 2 + 10 = 20
-2 does not work
Does 2.5 work?
2(2.5)^2 - 2.5 + 10 =
2*6.25 - 2.5 + 10 = 20
2.5 does not work

Answer 2

Choice a does not work

Answer 3

ok

Answer 4

so for the next 2 parts i got 14.9028 and 20.5. so the answer would have to be D right?

Answer 5

Now you can do the same method for choice B
2x^2 - x + 10 = 0
Let x = -1.97 (choice b)
2(-1.97)^2 - (-1.97) + 10 =
7.76 + 1.97 + 10 = 19.73
-1.97 does not work

Answer 6

You still need to check c.

Answer 7

c i got 20.5. is that right?

Answer 8

Let's try -2.5
2(-2.5)^2 - (-2.5) + 10 =
12.5 + 2.5 + 10 = 25
-2.5 does not work, so c also does not work, so d is correct

Answer 9

k. thanks!