How to write four hundred twelve thousand, nine hundred eighty seven in standard form

What is the answer to this question? i'm a bit stumped. also how do i do it? 5(x - 4) = 2(x + 5)

Mr. thompson is on a diet. he currently weighs 260 pounds. he loses 4 pounds per month. what part of the story makes the relationship not proportional?

Afactory buys 10% of its components from suppliers b and the rest from supplier c. it is known that 6% of the components it buys are faulty. of the components brought from suppliers a,9% are faulty and of the components bought from suppliers b, 3% are faulty. find the percentage of components bought from supplier c that are faulty.