Answer:
1) x=9
edit:
2) x=25
Step-by-step explanation:
Since all angles added together in any triangles is 180,
we can conclude that
180=(7x-1)+(5x+2)+(7x+8)
solving for x:
180=19x+9
180-9=19x
171=19x
x=9
Edit:
2)since we are given the outside angle we have to find the inside one first before finding the other angles, a straight line is 180 degrees aswell, so 180-(3x-10) would give you the inside angle in terms of x
so adding them all together again should ewual 180:
180=(180-(3x-10))+25+(x+15)
180=180-3x+10+25+x+15
0=-2x+50
2x=50
x=25
