Answer:
x = 3 and x=-6/5
Step-by-step explanation:
x = one integer
y = other integer
One integer is 9 less than 5 times another
x= 5y-9
product is 18
xy = 18
Substitute in for x
(5y-9) *y = 18
Distribute
5y*y -9y = 18
5y^2 - 9y = 18
Subtract 18 from each side.
5y^2 - 9y -18= 18-18
5y^2 - 9y -18 = 0
Using the quadratic formula
-b ± sqrt(b^2 -4ac)
-----------------------
2a
-(-9) ±sqrt(9^2 -4*5*(-18))
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2(5)
9 ±sqrt(81 +360))
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10
9 ±sqrt(441)
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10
9±21
----------
10
x = (9+21)/10 and x = (9-21)/10
x = 30/10 and x = (-12)/10
x = 3 and x=-6/5
