Solve for x if EF=6x-7 and FG=3x-5

You have 6 dollars +12 pennies +to quarters + 4 dimes=2 nickels how much do you have

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?

Can someone tell me if this is perpendicular? !