Answer:
x = 2
Step-by-step explanation:
x + 3 = -x + 7
Add x to each side
x+x + 3 = -x+x + 7
2x+3 = 7
Subtract 3 from each side
2x = 7-3
2x = 4
Divide by 2
2x/2 = 4/2
x = 2
7 2/6 + 8 5/6
= (7 x 6 + 2)/6 + (8 x 6 + 5)/6
= (42 + 2)/6 + (48 + 5)/6
= 44/6 + 53/6
= (44 + 53)/6
= 97/6
= 16 1/6
Number 4: line XZ; number 5: theory of congruent triangles.