Write the sentences below as a mathematical expression. 1. the sum of a number and 9 2. 12 decreased by some number 3. some number decreased by 7 4. twice a number 5. 2 times a number 6. a number dived by 8 7. the quotient of a number and 3 8. double the sum of 8 and a number

If 2(a^2+b^2)=(a+b)^2 then, > a+b=0, > ab=0, > a=b, > 2a=b

Describe a situation that you could represent with the inequality x< 17

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?