Question

ABCD is a parallelogram. Determine the measure of ∠B.

https://snag.gy/wTpPAq.jpg

Answer 1

opposite angles are equal therefore

6x + 14 = 9x - 7

first solve for x, and then *** this is important*** you must plug that value of x back into <B = 9x - 7 to get angle <B

lmk if anything was unclear or if you just want to check your solution

Answer 2

can you maybe show me exactly how to solve it?

Answer 3

sure

6x + 14 = 9x - 7

since we have 6x on the left side, we can subtract 6x from both sides to get

6x - 6x + 14 = 9x - 6x - 7

9x - 6x = 3x
6x - 6x = 0

therefore:

14 = 3x - 7

know where to go from there? how might we isolate 3x?

Answer 4

im really unsure, do we have to put 3x in something like parenthesis?

Answer 5

since we have "3x - 7" on the right side and we only want "3x" how might we "undo" the -7? what's the opposite of subtracting 7?

Answer 6

opposite of subtracting 7? would it be adding 7?

Answer 7

good, and since we added +7 to the right side we must also add 7 to the left side to keep things equal

14 = 3x - 7

becomes

14 + 7 = 3x

any ideas where to go from here?

Answer 8

add the 14+7?

Answer 9

good

so 14 + 7 = 21

3x = 21

know how we can find x?

Answer 10

um im not sure

Answer 11

since 3 is being multiplied to x, we can divide by 3 to "get rid of" that 3

so 3x/3 = x = 21/3 = 7

therefore, x = 7

now, we want to know what angle B is

so <B = 9x - 7 = 9(7) - 7 = ?

Answer 12

9(7) - 7 do you want me to solve this?

Answer 13

yes

Answer 14

56?

Answer 15

good so 56 degrees = your solution

Answer 16

good so 56 degrees = your solution

Answer 17

ohh kk ty soo much!