find the value of x. please show step by step!! will award brainliest :)

Answer:
x=21 degrees
Step-by-step explanation:
<J congruent <E (Base Angles Theorem)
90+(7x+3)+(7x+3)=180 (Sum of Angles in a Triangle)
96+14x=180 (Algebra and Substitution)
180-96=`4x
84=4x
x=84:4
x=21
Hope this helps! <3