SOLUTION: 8. solve for x: (3 + 2i) + (4 + xi) = 7 - 5i 9. Which of the following is not sufficient to prove that a quadrilateral is a parallelogram? (1) opposite sides are congruent (

Algebra.Com
Question 173132This question is from textbook Amsco's Preparing for the Regents Examination Mathematics B
: 8. solve for x: (3 + 2i) + (4 + xi) = 7 - 5i
9. Which of the following is not sufficient to prove that a quadrilateral is a parallelogram?
(1) opposite sides are congruent (2) opposite angles are congruent
(3) diagonals are congruent (4) consecutive angles are supplementary

Show work please, thank you!
This question is from textbook Amsco's Preparing for the Regents Examination Mathematics B

Found 2 solutions by stanbon, user_dude2008:
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
8. solve for x: (3 + 2i) + (4 + xi) = 7 - 5i
7 + (2+x)i = 7 - 5i
2+x = 5
x = 3
----------------------------
9. Which of the following is not sufficient to prove that a quadrilateral is a parallelogram?
(1) opposite sides are congruent (2) opposite angles are congruent
(3) diagonals are congruent (4) consecutive angles are supplementary
Draw the pictures of the various conditions; see if you get a parallelogram
under each condition.
===============================
Cheers,
Stan H.

Answer by user_dude2008(1862)   (Show Source): You can put this solution on YOUR website!
8)

(3 + 2i) + (4 + xi) = 7 - 5i


(3 + 4) + (2i + xi) = 7 - 5i


-----> 3+4 = 7 and 2i+xi=5i

2i+xi=-5i

xi=-7i

x=-7 <----answer



9)

Which of the following is not sufficient to prove that a quadrilateral is a parallelogram?


The answer is (4) consecutive angles are supplementary


Example:

Draw a trapezoid with the top and bottom parallel. Now make one side completely vertical. This will make 2 consecutive angles that add to 180, but it won't be a parallelogram

RELATED QUESTIONS

Solve the following for x: {{{ (1 + xi)(3 + 2i) = 1 + 5i... (answered by josgarithmetic,math_helper)
6) The test scores in Mrs. Kaste's Math B class are normally distrubuted with a mean of... (answered by nycsub_teacher)
Quadrilateral lkmn has vertices k(x, y) ,L(0, 3) M (8,-9) and N (9,-6) the equation of... (answered by lynnlo)
1) Is it sufficient to know the slope of the sides to determine whether a quadrilateral... (answered by richard1234)
my earlier submission looks to be jumbled. I have tried to put the same questions in a... (answered by CharlesG2)
1.A 95% confidence interval for the mean of a normal population is found to be 17.6 < µ < (answered by stanbon)
let a be an nxn matrix. let Ax=b be the matrix equation for a linear system in which b... (answered by robertb)
9) the expression i to the 25 power is eqivalen to? a) -i b)1 c)i d)-1 10) What... (answered by Alan3354)
If two sides of a triangle are equal to 3 and 7, which of the following is not a possivle (answered by MathLover1)