No real solution is the answer Quiz 5 February 26, 2021 MAT 140 DCO = 3- 131 7. (13 pts) Solve the quadratic equation -2x2 + 3x - 5 = 0 4 An - 3 2 + 5 =0 comparing with a x+ box +c = 0 4 a = 2 , / = - 3 , C= 5 we know that stoution of equestion shriday mayor formiles X = - bt J ac 34 - 31 3 Only using rex 4 solutions. 4 i= NO Real 2 X2 X 3 + 1 1 31 Solu 9 - Ao X 3 30 73 4 8. (13 pts) A store has been selling 220 flat-screen TVs a week at $430 each. A market survey indicates that for each $25 rebate offered to buyers, the number of TVs sold will increase by 15 a week. How large of a rebate should the store offer to maximize its revenue? Hint: Revenue is price times quantity. RC ) = (A 30 - 25 x ) ( 15x+ 220 ) 430 - 25 x ( 15X + 220) + (430- 25x ) xd dx 15x+ 220 ax ( 430 ) - 25. d dix ( * ) ) ( 15* + 2 20 ) + ( 430 - 25 x ) ( 15 . - ( * ) + d ( 220 R (x ) = ( 15* + 220) (-25 *+430 ) (0 -25 . 1) (15x+ 220) + (430- 25x) (15.1+0) = 15( 430-25x 25 /15X +22