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What 2 numbers add to get -9 and multiply to get -30?​

1 Answer

4 votes

Answer:


y_(1)=-(9)/(2)-(√(201))/(2) or
y_(2)=-(9)/(2)+(√(201))/(2)


x_(1)=-(9)/(2)-(√(201))/(2) or
x_(2)=-(9)/(2)+(√(201))/(2)

Explanation:

Let be x the first number and y the second number.

So we have:


x+y=-9 (1)


x*y=-30 (2)

Solve x from equation 1 and put it into equation 2


x=-9-y


(-9-y)*y=-30


-9y-y^(2)=-30


y^(2)+9y-30=0

Solving this quadratic equation and put it on the equation (1) the solutions will be:


y_(1)=-(9)/(2)-(√(201))/(2) or
y_(2)=-(9)/(2)+(√(201))/(2)


x_(1)=-(9)/(2)-(√(201))/(2) or
x_(2)=-(9)/(2)+(√(201))/(2)

I hope it helps you!

User Rmic
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