Answer:
C
Step-by-step explanation:
Bc i'm smart and i know things
We need to solve the following system by substituition:

To solve by substituition means that we need to isolate one variable in one of the equations and replace one expression with the other. This is done below:

Then we need to replace the value of "x" in any of the two equations.

The solution is (-3,-5).
Answer:
43 messages
Step-by-step explanation:
Given:
146 messages = $21.90
x messages = $6.45
Finding x by cross-multiplication:
x = 146*6.45/21.90 = 43
Hope this helps! :)
Answer:
z= 27/4
Step-by-step explanation:
Answer:
The height of the lamp is 18.33 ft
Step-by-step explanation:
We can think in two triangle rectangles, one with cathetus of:
5.5ft and 6ft (the one formed by the woman ad her shadow)
And another triangle with cathetus equal to:
6ft + 14ft (the distance between the end of the shadow and the lamp)
And the other cathetus is the height of the lamp, H.
As bot triangles will share an angle (the one formed by the end of the shadow and the hypotenuse) then the triangles are equivalent, so the quotient between their cathetus will be equal, this is:
H/(6ft + 14ft) = 5.5ft/6ft
H/(20ft) = 5.5ft/6ft.
H = (5.5ft/6ft)*20ft = 18.33 ft