To find the area of a rhombus, the formula is d1(d2)/2
d1 is 4+4 or 8
d2 is 7+10 or 17
17(8)=136
136/2=68
3-7 is -4 so it becomes -4x=4 divide both sides by 4 to get -x=-1 a lot of teachers dont like that negative x so you can also divide by -1 again to make it x=1
hope it helps
Sorry, I didn't quite understand the question here is a clear one, it was made by me personally in the geo-gebra application
80 because it should be the same as the other one