Answer:


Step-by-step explanation:
Given :
...................... equation 1
........................ equation 2
solving the system of linear equation by substitution method , substitute equation 1 into equation 2 , that is



collect the like terms

therefore :

substitute
into equation 1 to find the value of y , that is


Therefore :


The question reminds you of all the tools you need:
It says ...
"Opposite angles are equal."
So the upper right angle is x+40 just like the bottom left,
and the bottom right angle is 3x+20 just like the upper left.
And it says ...
"The sum of all angles is 360°."
You know what each of the four angles is, so you can addum all up,
set the sum equal to 360, find out what number ' x ' is, and then
use that to find the size of every angle.
Answer:
d i believe b is your answer your welcome