Answer:
x = -44/13
y = -65/13
Step-by-step explanation:
Using matrix form means using the crammers rule
The matrix form of the expression is written as;
AX = B
taking the determinant of A;
|A| = 8(1) - 5(-1)
|A| = 8 + 5
|A| = 13
After replacing the first row with the column matrix;
|Ax| = 9(-1)-5(7)
||Ax| = -9 - 35
|Ax| = -44
x = |Ax|/|A|
x = -44/13
similarly for y
|Ay| = 8(7)+9
|Ay| = 56+9
|Ay| = 65
y = |Ay|/|A|
y = -65/13
Answer:
y= -2x²+4x.
Step-by-step explanation:
the common equation of the parabola is y=ax²+bx+c, where a, b, c - numbers.
1) the coordinates of the vertex are:
2) if according to the condition x₀=1, then b= -2a.
If according to the condition y₀=2, then
it means that c=a+2.
3) if b= -2a; c=a+2 and the point (3;-6) belongs to the given parabola, then it is possible to substitute them into the common equation of the parabola:
-6=3²*a-6a+a+2; ⇔ a= -2.
4) if a= -2, then b=-2a=4, and c=a+2=0.
5) if a=-2, b=4 and c=0, then the required equation of the parabola is:
y= -2x²+4x.