Question

Solve by substitution.
x+7y=45
2x+7y=41

Answer 1

from the first equation

x=45-7y
put this into the second equation
2(45-7y)+7y=41

solve for y
plug value of y back into x=45-7y to get value of x

Answer 2

you should get x=-4 and y=7

Answer 3

Take the first equation and subtract the 7y to both sides and gives you
x=-7y+45

next take the other equation and plug it in to make
2(-7y+45)+7y=41

distribute
-14y+90+7y=41

combine like terms
-7y+90=41

subtract 90 to both sides
-7y=49

divide by -7 to both sides
y=-7

that is your y-coordinate

next, plug it into the other equation to get the x

Answer 4

"subtract 90 to both sides -7y=49"

-7y=-49