Help plss i need help

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

Which statement justifies why angle ebc measures 90?

Ten members of balin's soccer team ran warm ups for practice. each member ran the same distance. their combined distance was 5/6 of a mile. to find the distance that each member ran, balin wrote the expression below.