By rounding to 1 significant figure, estimate the answers to these questions:

346 x 904

What is the factored form of the following expressions? d^2 – 13d + 36

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?

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25