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

$RS + ST = RT$

$23-2x+9x-5=39$

$18+7x=39$

$7x=21$

$x=3$

$RS = 23-2*3=23-6=17$

$LN+LM=MN$

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

$4x=18$

$x=4.5$

$MN=3*4.5+20=13.5+20=33.5$

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

$x_c = \dfrac{x_a+x_b}{2}=\dfrac{-3-7}{2}=-5$

$y_c = \dfrac{y_a+y_b}{2}=\dfrac{8-6}{2}=1$

C(-5;1) - the midpoint of AB

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

$AB=AE-BC-CE$

$AB = 7x-1-9x+2-10x-18=-12x-17$