Question
If 4x + 1/5x = 4, then find value of 125x³ +
1/64x³?Solution
4x + 1/5x = 4 By multiplying 5/4 , 4x × 5/4 + 1/5x × 5/4 = 4 × 5/4 5x + 1/4x = 5 On cubing both the sides, (5x+1/4x)^3 = (5)³ = 125x³ + 1/64x³ + 3 × 5x × 1/4x (5x+1/4x) = 125 = 125x³ + 1/64x³ + (3×5)/4 × 5 = 125 = 125x³ + 1/64x³ + 75/4 = 125 = 125x³ + 1/64x³ = 125 - 75/4 = 125x³ + 1/64x³ = (500-75)/4 = 125x³ + 1/64x³ = 425/4
More Algebra Questions
70.008% of 399.98 + ?% of 399.999 = 80.105% of 599.998
(278% of 695) ÷ 543 =?
A certain sum of money invested at R% p.a. fetches a compound interest (compounded annually) of 1620 and simple interest of Rs.1500 at the end of 2 year...
- What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)
(11.99)2 + 171.16 + (3.33) 2 = ?2Â
(21.02%  of 600.15 ) × 14.95 = ? 2 + 29.99 × 3456 ÷ 1152
20% of 80 × 26% of 65 = ?
(0.89 3 + 1.64 3 +2.76 3 ) ÷ 5.89 = ?
- What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)
- What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)
