Question

4х*(2х^14)^5:(2х^10)^7,при х=90

Answer 1

$\displaystyle4x\times(2x^{14})^5\div(2x^{10})^7=4x\times\frac{(2x^{14})^2}{(2x^{14})^2}\times\\\times(2x^{14})^5\div(2x^{10})^7=4x\times\frac{(2x^{14})^7}{(2x^{14})^2}\div(2x^{10})^7=\\=4x\times\frac{(2x^{14})^7}{(2x^{14})^2\times(2x^{10})^7}=4x\times\frac{128x^{98}}{4x^{28}\times128x^{70}}=\\=4x\times\frac{x^{28}}{4x^{28}}=\frac{4x}{4} =x=90$

Answer 2

2²*х*2⁵*х¹⁴*⁵*2⁻⁷*х⁻¹⁰*⁷=2²⁺⁵⁻⁷*х¹⁺⁷⁰⁻⁷⁰=2⁰*х=х=90