Can someone me out with this? i''m not understanding how to solve these.
2y-4x=20
y+4x=1

You can use substitution. Using the second equation, you move the variables to different sides and end up with y=1-4x then you substitute this into the first equation. You will get 2(1-4x)-4x=20 then you simplify. Distribute the 2 to get 2-8x-4x=20. Then combine like terms to get -12x=18. Divide each side by -12 and you get x=-18/12 or -3/2. Then you plug this number into either equation to find y. y+ 4(-3/2) =1 then distribute 4. y-6 =1. Then you get y=7. You can check your answer by plugging in both x and y and seeing if the equation remains true. 7+ (4•-3/2) =1 is true. So your answer is (-3/2, 7)

The answer would be 24mm