Answer:
Either one: the two line have a point in common, or infinite: they are the same line.
m∠DWC=138°, ∠AWB = 138°, ∠AWD = 42°, ∠BWC = 42°
Solution:
Line 
intersect at a point W.
Given 
.
<em>Vertical angle theorem:</em>
<em>If two lines intersect at a point then vertically opposite angles are congruent.</em>
<u>To find the measure of all the angles:</u>
∠AWB and ∠DWC are vertically opposite angles.
Therefore, ∠AWB = ∠DWC
⇒ ∠AWB = 138°
Sum of all the angles in a straight line = 180°
⇒ ∠AWD + ∠DWC = 180°
⇒ ∠AWD + 138° = 180°
⇒ ∠AWD = 180° – 138°
⇒ ∠AWD = 42°
Since ∠AWD and ∠BWC are vertically opposite angles.
Therefore, ∠AWD = ∠BWC
⇒ ∠BWC = 42°
Hence the measure of the angles are
m∠DWC=138°, ∠AWB = 138°, ∠AWD = 42°, ∠BWC = 42°.
Solve:
"<span>twice the number minus three times the reciprocal of the number is equal to 1."
3(1)
Let the number be n. Then 2n - ------- = 1
n
Mult all 3 terms by n to elim. the fractions:
2n^2 - 3 = n. Rearranging this, we get 2n^2 - n - 3 = 0.
We need to find the roots (zeros or solutions) of this quadratic equation.
Here a=2, b= -1 and c= -3. Let's find the discriminant b^2-4ac first:
disc. = (-1)^2 - 4(2)(-3) = 1 + 24 = 25.
That's good, because 25 is a perfect square.
-(-1) plus or minus 5 1 plus or minus 5
Then x = ------------------------------ = --------------------------
2(2) 4
x could be 6/4 = 3/2, or -5/4.
You must check both answers in the original equation. If the equation is true for one or the other or for both, then you have found one or more solutions.</span>
The decimal form for nine and fifteen thousandths is 09.15
C. The first is a solution, but the second is not.
5x - y/3 = 13 ; (2,-9)
substitute the letters:
5(2) - (-9/3) = 13
10 - (-3) = 13 : note that deducting a number with a negative sign turns both sign as positive.
10 + 3 = 13 ;
13 = 13
5x - y/3 = 13 ; (3,-6)
5(3) - (-6/3) = 13
15 - (-2) = 13
15 + 2 = 13
17 = 13 not equal. not a solution
hope i could help
