Question

I need help!!!!!!!!!!!!!!!!!!!

Answer 1

B. 0.25x² + 0.8x - 8 = 0

C. 5x² + 7x = 15

Explanation:

Let's try by solving all equations;

(x + 3)² = 36

x² + 3² = 36

x² + 9 = 36

x² = 36 - 9

x² = 27

x = √27

x ≈ 5.2

No quadratic

What about others

0.25x² + 0.8x - 8 = 0

Hmm.... that can only be solved by quadratic

`\sf { \fbox{0.25x² + 0.8x - 8 = 0} \: can \: only \: be \: solved \: by \: quadratic}`

Also, 5x² + 7x = 15

`\sf { \fbox{5x² + 7x = 15} \: can \: only \: be \: solved \: by \: quadratic}`

(x + 8)(x + 9) = 0

x² + 9x + 8x + 72 = 0

x² + 17x + 72 = 0

(x + 8)(x + 9) = 0

Not truly quadratic but can be solved with quadratic.

That leaves us with only B and C as the answer