Hello!
For this problem we are given that quadrilateral ABCD is congruent to quadrilateral GJIH, meaning that all sides and angle measures will be equivalent to its corresponding side.
This means that to find
, we can look at quadrilateral GJIH's corresponding side to quadrilateral ABCD's side AD, which is side GH, which has a value of 9.
This means that 9 should also be the side length of side AD, which we're given a value of
.

Solve.

Hope this helps!
Answer:
It would be -81²x+81x-18= -9x+6
Step-by-step explanation:
When you work equation one you get 18. Then when you work equation two, you get -2/3=-0.666666667
Answer:
(3, - 1 )
Step-by-step explanation:
Given the 2 equations
3x + y = 8 → (1)
7x - 4y = 25 → (2)
Multiplying (1) by 4 and adding to (2) will eliminate the y- term
12x + 4y = 32 → (3)
Add (2) and (3) term by term to eliminate y
19x + 0 = 57
19x = 57 ( divide both sides by 19 )
x = 3
Substitute x = 3 into either of the 2 equations and solve for y
Substituting into (1)
3(3) + y = 8
9 + y = 8 ( subtract 9 from both sides )
y = - 1
solution is (3, - 1 )