Question

Solve 47 (math operation)

Answer 1

Answer:

  t ≈ -2.014 or 3.647

Step-by-step explanation:

Add the opposite of the expression on the right side of the equal sign to put the equation into standard form.

  4.9t² -8t -36 = 0

You can divide by 4.9 to make this a little easier to solve.

  t² -(8/4.9)t -36/4.9 = 0

Now, add and subtract the square of half the x-coefficient to "complete the square."

  t² -(8/4.9)t +(4/4.9)² -36/4.9 -(4/4.9)² = 0

  (t -4/4.9)² -192.4/4.9² = 0 . . . . simplify

Add the constant term, then take the square root.

  (t -4/4.9)² = 192.4/4.9²

  t -4/4.9 = ±(√192.4)/4.9

  t = (4 ± √192.4)/4.9

  t ≈ {-2.014, 3.647}