Please Help c:
What are the solutions to the following system of equations?
y = x2 + 12x + 30
8x − y = 10

(−4, −2) and (2, 5)

(−2, −4) and (2, 5)

(−2, −4) and (5, 2)

No Real Solutions

Question

Please Help c:
What are the solutions to the following system of equations?
y = x2 + 12x + 30
8x − y = 10 

 (−4, −2) and (2, 5) 

 (−2, −4) and (2, 5) 

 (−2, −4) and (5, 2) 

 No Real Solutions

anonymous · Answer

What is the solution to the following system of equations?
y = x2 + 10x + 11
y = x2 + x − 7 

 (−2, −5) 

 (2, −5) 

 (−2, 5)

campbell_st · Answer

rewrite the 2nd equation with y as the subject
y = 8x - 10

now equate it to the 1st equation and you get

$$8x - 10 = x^2 + 12x + 10$$

now you have 1 equation in 1 unknown to solve

anonymous · Answer

y = x2 + 12x + 30
8x − y = 10 
express y from second equation: $y=8x-10$
substitute in the 1º equation: $8x-10=x^2 + 12x + 30$
rearange terms: $x^2+4x+40=0$
solve this. You will get 2 solutions, which later substitute in the 2º equation to get corresponding y value

campbell_st · Answer

oops should be '

$$8x - 10 = x^2 + 12x + 30$$

just solve for x

anonymous · Answer

Mm.. ill try. One sec, ill let you know what I get

missmob · Answer

:O maths

campbell_st · Answer

and can you check your equations as they may be a typo in them...

nirmalnema · Answer

you can get the ans by by making the quadratic eq..in x

missmob · Answer

we will put all the x on one side

anonymous · Answer

The what? LOL

campbell_st · Answer

because based on the information there are any solutions that are real numbers

campbell_st · Answer

oops... which is an option

campbell_st · Answer

sorry...

anonymous · Answer

Ok.. so its D.. cool

missmob · Answer

maths is confusing

anonymous · Answer

But idk how to get D

missmob · Answer

*takes out the gun shoots maths*

campbell_st · Answer

well do you know about the discriminant...? thats how you check...

anonymous · Answer

lol...

anonymous · Answer

No.. but I got 8x-10=x2+12x+30 so far..

anonymous · Answer

What do I do from there?

campbell_st · Answer

subtract 8x from both sides... 

then add 10 to both sides of the equation...

anonymous · Answer

Oh.. I knew that. For some reason I thought I needed to bring my X from the right to the left.

anonymous · Answer

Ok.. so I got x=x2+4x+40
Is that right?

nirmalnema · Answer

ya you got it right

campbell_st · Answer

and the discriminant is for a quadratic 

$$ax^2 + bx + c = 0$$

thew discriminant is 

$$b^2 - 4ac$$

you have a = 1, b = 4 and c = 40

it will be less than zero... meaning complex roots

anonymous · Answer

Sooo its D.

anonymous · Answer

Thanks everyone! c: