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Reason Abstractly Find two integers whose sum is -7 and whose

product is 12. Explain how you found the numbers.

User GDmac
by
6.2k points

2 Answers

1 vote

Answer: -3 and -4

Step-by-step explanation: you can use a system of equations.

x+y=-7

xy=12

Solve for x

x=-7-y

Replace x in the other equation and solve for y

(-7-y)y=12

y^2+7y+12=0

(y+3)(y+4)=0

y+3=0 y+4=0

y=-3 y=-4

User Allen Rohner
by
5.8k points
4 votes

Explanation:

Let's represent the two integers with the variables
x and
y.

From the problem statement, we can create the following two equations:


x + y = -7


xy = 12

With the first equation, we can subtract
y from both sides to isolate the
x variable to the left-hand side:


x = -7 - y

Now that we have a value for
x, we can plug it into the second equation and solve for
y:


(-7 - y)y = 12


-7y - y^(2) = 12

Now, let's move everything to one side of the equation:


y^(2) + 7y + 12 = 0

Factoring this quadratic will give us two values for
y:


(y + 4)(y + 3) = 0


y = -3, -4

Since we now know
y = -3, -4, we can plug this back into either of the original equations to get a value for
x, which will be
x = -4, -3.

So the two numbers that sum to
-7 and have a product of
12 are
-3, -4.

User CaNNaDaRk
by
6.1k points