What is an inequality? where would u use them in the real world

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

Desmond wants to sell his car that he paid $8,000 for 2 years ago. the car depreciated, or decreased in value, at a constant rate each month over a 2-year period. if x represents the monthly depreciation amount, which expression shows how much desmond can sell his car for today? 8,000 + 24x 8,000 - 24x 8,000 + 2x 8,000 - 2xdesmond wants to sell his car that he paid $8,000 for 2 years ago. the car depreciated, or decreased in value, at a constant rate each month over a 2-year period. if x represents the monthly depreciation amount, which expression shows how much desmond can sell his car for today? 8,000 + 24x 8,000 - 24x 8,000 + 2x 8,000 - 2x

Bobs burgers bam has a special deal of 4 hamburgers for $6. at that rate, how much should it cost to buy 3 hamburgers?