If 4 sandwich rolls cost $0.64,how much will 21 rolls cost ?

Trigonometry help asap

Pls brainliest will be awarded if answer is correct

Which equation shows the quadratic formula used correctly to solve 5x2 + 3x -4 0 for x? cos -3+ v (3) 2-4() 2(5) 3+ |(3)² +4() 205) 3+ (3) 2-4() -3+ v (3)² +4()