Answer:
t = 36
Explanation:
If you divide the equation by 5, you have ...
... x^2 -7.2x +t/5 = 0
The opposite of the sum of the roots is the coefficient of the linear term, so is 7.2. If the roots are "r" and "5r", then their sum is r+5r = 6r, so the value of r is ...
... 7.2/6 = 1.2
The roots are 1.2 and 5·1.2 = 6.
The constant term t/5 is the product of the roots, so ...
... t/5 = 1.2 · 6
... t = 6·6 = 36 . . . . . multiply by 5