Answer:
- r1 +4×r3 ⇒ r1
- r2 -3×r3 ⇒ r2
Step-by-step explanation:
We note that the coefficient of y in equation (iii) is 1, so it is convenient to use that equation to eliminate y from the others.
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<em>To eliminate the y-variable from equation (i), four times equation (iii) can be added to equation (i).</em>
<em>To eliminate the y-variable from equation (ii), three times equation (iii) can be subtracted from equation (i).</em>
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The result of these operations would be ...
÷
Multiply
by the reciprocal of
, which is
=
×
=
We can simplify it further:
The greatest common factor here is
168
=
Answer: A
Step-by-step explanation:
Answer:
13.98 in²
Step-by-step explanation:
I don't understand it, either.
Point N is part of a "segment" that above and to the right of chord MO. It is the sum of the areas of 3/4 of the circle and a right triangle with 7-inch sides. The larger segment MO to the upper right of chord MO has an area of about 139.95 in², which <u>is not</u> an answer choice.
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The remaining segment, to the lower left of chord MO does not seem to have anything to do with point N. However, its area is 13.98 in², which <u>is</u> an answer choice. Therefore, we think the question is about this segment, and we wonder why it is called MNO.
The area of a segment is given by the formula ...
A = (1/2)(θ -sin(θ))r² . . . . . . where θ is the central angle in radians.
Here, we have θ = π/2, r = 7 in, so we can compute the area of the smaller segment MO as ...
A = (1/2)(π/2 -sin(π/2))(7 in)² = 24.5(π/2 -1) in² ≈ 13.9845 in²
Rounded to hundredths, this is ...
≈ 13.98 in²
First we'll do two basic steps. Step 1 is to subtract 18 from both sides. After that, divide both sides by 2 to get x^2 all by itself. Let's do those two steps now
2x^2+18 = 10
2x^2+18-18 = 10-18 <<--- step 1
2x^2 = -8
(2x^2)/2 = -8/2 <<--- step 2
x^2 = -4
At this point, it should be fairly clear there are no solutions. How can we tell? By remembering that x^2 is never negative as long as x is real.
Using the rule that negative times negative is a positive value, it is impossible to square a real numbered value and get a negative result.
For example
2^2 = 2*2 = 4
8^2 = 8*8 = 64
(-10)^2 = (-10)*(-10) = 100
(-14)^2 = (-14)*(-14) = 196
No matter what value we pick, the result is positive. The only exception is that 0^2 = 0 is neither positive nor negative.
So x^2 = -4 has no real solutions. Taking the square root of both sides leads to
x^2 = -4
sqrt(x^2) = sqrt(-4)
|x| = sqrt(4)*sqrt(-1)
|x| = 2*i
x = 2i or x = -2i
which are complex non-real values
