Math problems in grade three explain algebraic expressions by collocation-10x? 0? The value of 5+7x-4 is always less than 0.
Solution:-10x? 0? 5+7x-4=- 10[x？ 0? 5-2*7/20+(7/20)? 0? 5-(7/20)? 0? 5+4/ 10]=- 10[(x-7/20)？ 0? 5-49/400+ 160/400]=- 10[(x-7/20)？ 0? 5+111/400] Why (x-7/20)? 0? 5≥0, so (x-7/20)? 0? 5+111/400 > 0 is a constant in the real number range, so-10x? 0? 5+7x-4=- 10[(x-7/20)？ 0? 5+111/400] < 0.