Answer:
1) x=10
2) x=6
3) x=13
Step-by-step explanation:
1) 15x-17+4x+7=180
19x-10=180
19x=190
x=10
2) 13x+5=16x-13
5+13=16x-13x
18=3x
x=6
3) 9x+7=11x-19
7+19=11x-9x
26=2x
x=13
78
58.0
Literally, i just counted since it's odd and it just lands on 1 number which was 58.0