Solve the equation by completing the square. 0=4x^2-72x
2 answers:
Answer:
Step-by-step explanation:
First we need to make sure that the leading coefficient is a 1. Ours is a 4, so we need to factor it out, leaving us with
To complete the square, take half the linear term, square it, then add it to both sides. But don't forget about that 4 hanging around out front, refusing to be ignored. Our linear term is 18. Half of 18 is 9, and 9 squared is 81. Add 81 into the parenthesis, but what we REALLY added in was 4*81 which is 324:
To solve this, we need to get the x terms all by themselves. So let's divide both sides by 4 to get
The process of completing the square created a perfect square binomial on the left. We will state this binomial now:
We isolate the x term by taking the square root of both sides:
x - 9 = ±9
From that we have 2 equations:
x - 9 = 9 and x - 9 = -9
Which means that x = 18 or x = 0
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Answer:
Option A is correct (17,11).
Step-by-step explanation:
6x - 9y = 3
3x - 4y =7
it can be represented in matrix form as
A=
X=
B=
i.e, AX=B
or X= A⁻¹ B
A⁻¹ = 1/|A| * Adj A
determinant of A = |A|= (6*-4) - (-9*3)
= (-24)-(-27)
= (-24) + 27 = 3
so, |A| = 3
Adj A=
A⁻¹ = /3
A⁻¹ =
X= A⁻¹ B
X=
X=
X=
X=
x= 17, y= 11
solution set= (17,11).