F(x) = x² + x - 20 = x² + 5x - 4x - 20 = x(x + 5) - 4(x + 5) = (x + 5)(x - 4)

f(x) = 0 ⇔ (x + 5)(x - 4) = 0 ⇔ x + 5 = 0 or x - 4 = 0 ⇒ x = -5 or x = 4

Answer: C. x = -5 and x = 4.

3 0

3 years ago

How do you simplify this problem

vampirchik [111]

Reduce the fraction with 2
$\frac{2 \times x {}^{ - 2} y {}^{3}z {}^{ - 1} }{xy} \\ \\ \frac{3y {}^{2}z {}^{ - 1} }{x {}^{3} } \\ \\ \frac{3y {}^{2} }{x {}^{3} z}$

7 0

3 years ago

write the place value of the underlined digit. round each number to the place of the underlined digit 2.348 *3 is underlined*

write the place value of the underlined digit. round each number to the place of the underlined digit 2.348 3 is underlined