Saved Bookmarks
| 1. |
Sum of the roots of the equation4x - 3(2x + 3) + 128 = 0 is1. 52. 63. 74. 8 |
|
Answer» Correct Answer - Option 3 : 7 Concept: Base Rule If b raised to the xth power is equal to b raised to the yth power, that implies that x = y.” \(\rm b^x = b^y \) ⇒ x = y Calculations: Given equation is 4x - 3(2x + 3) + 128 = 0 ⇒ \(\rm (2^2)^x - 3 (2^x.2^3) + 128 = 0\) ⇒ \(\rm (2^x)^2 - 24 (2^x) + 128 = 0\) ⇒ \(\rm (2^x)^2 - 16 (2^x) - 8(2^x)+ 128 = 0\) ⇒ \(\rm (2^x - 16)(2^x - 8) = 0\) ⇒ \(\rm 2^x = 16 \;\;\text{or}\;\; 2^x = 8\) ⇒ \(\rm 2^x = 2^4 \;\;\text{or}\;\; 2^x = 2^3\) ⇒ x = 4 or x = 3 The roots of the equation 4x - 3(2x + 3) + 128 = 0 are 4 and 3 Its Sum = 4 + 3 = 7 |
|