answersLogoWhite

0

Still curious? Ask our experts.

Chat with our AI personalities

BeauBeau
You're doing better than you think!
Chat with Beau
CoachCoach
Success isn't just about winning—it's about vision, patience, and playing the long game.
Chat with Coach
ViviVivi
Your ride-or-die bestie who's seen you through every high and low.
Chat with Vivi
More answers
User Avatar

Wiki User

12y ago

1. x + y = 7

2. x * y = -30

Re-arrange 1. to y = -x + 7

Substitute this value for y into 2. gives:

3. x * (-x + 7) = -30

-x2 + 7x = -30

-x2 + 7x + 30 = 0

Now we can factor this quadratic to:

(-x + 10) (x + 3) = 0

Now we can make each bracket equal to 0 in turn.

-x + 10 = 0

-x = -10

x = 10

and

x + 3 = 0

x = -3

So the answer is 10 and -3.

User Avatar

Add your answer:

Earn +20 pts
Q: What adds up to 7 and multiply to get -30?
Write your answer...
Submit
Still have questions?
magnify glass
imp