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One of the roots of the equation 5x^2-36x+t=0 is five times as big as the other root. Find the value of t.

User Xorifelse
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1 Answer

10 votes

Answer:

t = 36

Step-by-step 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

User Chentingpc
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