Question

What is the value of 3x^4?

Answer 1

243

Explanation:

`5( \sqrt{ {x}^(2) + 2x - 14} + x) = 20 \\ \\ \sqrt{ {x}^(2) + 2x - 14} + x= (20)/(5) \\ \\ \sqrt{ {x}^(2) + 2x - 14} + x= 4 \\ \\ \sqrt{ {x}^(2) + 2x - 14} = 4 - x\\ \\ {(\sqrt{ {x}^(2) + 2x - 14} )}^(2) = {(4 - x)}^(2) \\ \\ \cancel{ {x}^(2)} + 2x - 14 = 16 - 8x + \cancel{ {x}^(2) } \\ \\ 2x - 14 = 16 - 8x \\ \\ 2x + 8x = 16 + 14 \\ \\ 10x = 30 \\ \\ x = (30)/(10) \\ \\ x = 3 \\ \\ 3 {x}^(4) = 3 {(3)}^(4) = 3 * 81 \\ \\ \huge \red {3 {x}^(4)= 243}`