Answer:
x=26
Explanation:
exterior angles theorem meaning they're equal to each other.
5x+7=8x-71
add 71 to 7
5x+78=8x
subtract 5x from 8x
78=3x
divide 78 and 3
x=26
to check your work plug 26 into each equation:
5(26)+7= 137°
8(26)-71= 137°
because they're the same you know that x must equal 26
hope this helps!❤