We need the graph to answer!
Answer:
here's the solution : -
=》2x - 3y = -29
=》x + 6y = 23
=》x = 23 - 6y
now, plugging the value of x in equation 1, we get : -
=》2x - 3y = -29
=》2 (23 - 6y) - 3y = - 29
=》46 - 12y - 3y = -29
=》-15y = -29 - 46
=》y = -75 ÷ -15
=》y = 5
now, plugging the value of y as 5 in equation 2
=》x + 6y = 23
=》x + (6 × 5.2) = 23
=》x = 23 - 30
=》x = - 7
The half-life of the radioactive substance is 67.95 hours.
16.79+28.49=45.28
50-45.28=4.72
Kelly would get $4.75 back
