Answer:
3x+2 + 6x+7 + 90 = 180
x=9
Step-by-step explanation:
Since JKL is a straight line, it equals 180
JKM + MKN + NKL = 180
3x+2 + 6x+7 + 90 = 180
Combine like terms
9x+99 = 180
Subtract 99 from each side
9x+99-99= 180-99
9x =81
Divide each side by 9
9x/9 = 81/9
x=9