Question

$y=5x^3-8x$ find y when x = 5

Answer 1

Answer:

585

Step-by-step explanation:

y = 5x³ - 8x     Let x = 5

  = 5(5)³ - 8 × 5

  = 5 × 125 – 40

  = 625 – 40

  = 585

Answer 2

For this case, we have an equation of the form$y = f (x)$, where $f (x) = 5x ^ 3-8x$, we must replace $x = 5$ in the following equation:

$y = 5x ^ 3-8x\\y = 5 (5) ^ 3-8 (5)\\y = 5 (5 * 5 * 5) -40\\y = 5 ^ 4-40$

Solving the power:

$5 ^ 4 = 5 * 5 * 5 * 5 = 625\\y = 625-40\\y = 585$

Answer:

$For\ x = 5,\ y = 585$