Answer:
x = -3
, y = 0
Step-by-step explanation:
Solve the following system:
{4 x - y = -12 | (equation 1)
-x - y = 3 | (equation 2)
Add 1/4 × (equation 1) to equation 2:
{4 x - y = -12 | (equation 1)
0 x - (5 y)/4 = 0 | (equation 2)
Multiply equation 2 by 4/5:
{4 x - y = -12 | (equation 1)
0 x - y = 0 | (equation 2)
Multiply equation 2 by -1:
{4 x - y = -12 | (equation 1)
0 x+y = 0 | (equation 2)
Add equation 2 to equation 1:
{4 x+0 y = -12 | (equation 1)
0 x+y = 0 | (equation 2)
Divide equation 1 by 4:
{x+0 y = -3 | (equation 1)
0 x+y = 0 | (equation 2)
Collect results:
Answer: {x = -3
, y = 0
Answer:
1. y = 9(x+1/2)^2 -13/4
Step-by-step explanation:
y = 9x^2 + 9x – 1
first isolate the x terms
y = 9(x^2 +x) -1
then add 1/4 inside the brackets to make it a perfect square trinomial (half of the coefficient of the x term squared is how we get 1/4)
since we just added 1/4 we need to subtract what we just added to balance the equation. so 1/4 times 9 is 9/4 ( the number we just added to the equation). then you subtract 9/4 outside of the brackets.
y = 9(x^2 +x +1/4) -1 -9/4
then simplify
y = 9(x+1/2)^2 -13/4
