Solve the following system using elimination:
{7 x + 2 y = -19 | (equation 1)
{2 y - x = 21 | (equation 2)
Add 1/7 × (equation 1) to equation 2:
{7 x + 2 y = -19 | (equation 1)
{0 x+(16 y)/7 = 128/7 | (equation 2)
Multiply equation 2 by 7/16:
{7 x + 2 y = -19 | (equation 1)
{0 x+y = 8 | (equation 2)
Subtract 2 × (equation 2) from equation 1:
{7 x+0 y = -35 | (equation 1)
{0 x+y = 8 | (equation 2)
Divide equation 1 by 7:
{x+0 y = -5 | (equation 1)
{0 x+y = 8 | (equation 2)
Collect results:
Answer: {x = -5, y = 8
Three times the difference of a number n and 1
For this case we have the following equation:
H (t) = - 16t ^ 2 + 28t
When the dolphin finishes a jump, then the height is equal to zero.
We have then:
-16t ^ 2 + 28t = 0
We look for the roots of the polynomial:
t1 = 0
t2 = 1.75 s
Therefore, the dolphin takes 1.75 seconds to make a jump.
Answer:
it will take for the dolphin to make one jump about:
t = 1.75 s
I'm assuming the question looks like this?

If so then the answer should be:

Hope this helps!