Question

Select the correct answer.

Answer 1

Answer:

Option C. The solution for the system of equations is (-1,7) and (-4,13)

Solution:

The equation for the system given is,

$y = -2x + 5$

$y=x^{2}+3 x+9$

Now we can write,

$-2 x+5=x^{2}+3 x+9$

$x^{2}+3 x+9+2 x-5=0$

$x^{2}+5 x+4=0$

$x^{2}+4 x+x+4=0$ (//simplifying)

$x(x+4) +1(x+4) = 0$

$(x+4)(x+1) = 0$

$x = -4 \ or -1$

When $x = -4, \ then \ y = -2\times(-4) + 5 =13$

When $x = -1, \ then \ y = -2\times(-1)+5 = 7$

So, solution is C,  (-4,13) and (-1,7)