Answer:
B. 28
Step-by-step explanation:
We are given the following system of equations
[tex]y=5x+10\\y=10x-5[/tex]
We can substitute in one of the equations for y. This will give us an equation that we can solve for x.
[tex]5x+10=10x-5\\\\5x=15\\\\x=3[/tex]
Next we can substitute in our value for x in order to find the y value.
[tex]y=5(3)+20\\\\y=15+20\\\\y=25[/tex]
Now we can check with the other equation to see if our x and y values are correct
[tex]25=10(3)-5\\\\25=30-5\\\\25=25[/tex]
Now we are certain that x=3 and y=25
[tex]x+y=?\\\\3+25=28[/tex]
