Question

If RS=23-2x,ST=9x-5,and RT=39 find RS.
RS=

If LN=6x-5,LM=x+7, and MN=3x+20 find MN
MN

Find X Round tithe nearest hundredth.
X(-9,2) and Y(5,-4)

Find the midpoint of AB if A(-3,8) and B(-7,-6)

If CE=10x+18,DE=7x-1 and BC=9x-2, find AB
X=
AB=

Answer 1

1.If RS=23-2x,ST=9x-5,and RT=39 find RS.

$rt = rs + st$

rt = 39

rs = 23 – 2x

st = 9x-5

$39 = (23 – 2x) + (9x - 5)$

$x = 3$

$rs = 23 - 2 * 3$

RS = 17

2.If LN=6x-5,LM=x+7, and MN=3x+20 find MN

$6*x - 5 = x + 7 + 3*x + 20$

$6x - 4x = 32$

$x = 16$

$MN = 3*16+20$

MN = 68

3.Find X Round tithe nearest hundredth.

X(-9,2) and Y(5,-4)

$d = \sqrt{ (5-(-9))^2 + (-4-2)^2}$

answer: 15.23

4.Find the midpoint of AB if A(-3,8) and B(-7,-6)

$midpoint = ((-3-7)/2; (8-6)/2)$

answer: (-5 , 1)

5.If CE=10x+18, DE=7x-1 and BC=9x-2, find AB

$CE=10x+18$

$DE=7x-1$

D is midpoint

$DE = 1/2CE$

$7*x - 1 = 1/2*(10*x+18)$

X=5

$CE = 10*5+18 = 68 = AC$

$BC = 9*x-2 = 9*5-2 = 43$

AB = AC - BC = 68-43 = 25

AB=25