A) Find a linear combination w of the linearly independent vectors v and u that is perpendicular to u. (b) For the 2-column matrix, find Q (orthonormal columns) and R (2 by 2 upper triangular) so that A= QR.​

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?