solve b

5a-3/a =3

7b-1=a-21

asked by guest
on Mar 28, 2025 at 12:29 pm



You asked:

Solve the equations 5a3a=37b1=a21\begin{aligned}5 a - \frac{3}{a} &= 3\\7 b - 1 &= a - 21\end{aligned} for the unknown bb.

MathBot Answer:

The system of equations has 22 solutions.

a=3106910,b=197706970a = \frac{3}{10} - \frac{\sqrt{69}}{10}, b = - \frac{197}{70} - \frac{\sqrt{69}}{70}a=310+6910,b=19770+6970a = \frac{3}{10} + \frac{\sqrt{69}}{10}, b = - \frac{197}{70} + \frac{\sqrt{69}}{70}


Solve 5a3a=35 a - \frac{3}{a} = 3 for aa. a=3106910,a=310+6910a = \frac{3}{10} - \frac{\sqrt{69}}{10}, a = \frac{3}{10} + \frac{\sqrt{69}}{10}Substitute 3106910\frac{3}{10} - \frac{\sqrt{69}}{10} for aa in 7b1=a217 b - 1 = a - 21 and solve.7b1=2071069107b=197106910b=197706970\begin{aligned}7 b - 1 &= - \frac{207}{10} - \frac{\sqrt{69}}{10}\\7 b &= - \frac{197}{10} - \frac{\sqrt{69}}{10}\\b &= - \frac{197}{70} - \frac{\sqrt{69}}{70}\end{aligned}This yields the following solution. a=3106910,b=197706970\begin{aligned}a = \frac{3}{10} - \frac{\sqrt{69}}{10},\,b = - \frac{197}{70} - \frac{\sqrt{69}}{70}\end{aligned}Substitute 3106910\frac{3}{10} - \frac{\sqrt{69}}{10} for aa in 7b1=a217 b - 1 = a - 21 and simplify. 7b1=a217b1=(3106910)21b=197706970\begin{aligned}7 b - 1 &= a - 21 \\ 7 b - 1 &= \left(\frac{3}{10} - \frac{\sqrt{69}}{10}\right) - 21 \\ b &= - \frac{197}{70} - \frac{\sqrt{69}}{70} \end{aligned}Substitute 197706970- \frac{197}{70} - \frac{\sqrt{69}}{70} into 7b1=a217 b - 1 = a - 21 to solve for aa. 207106910=a21a=310+6910a=3106910\begin{aligned}- \frac{207}{10} - \frac{\sqrt{69}}{10} &= a - 21\\- a &= - \frac{3}{10} + \frac{\sqrt{69}}{10}\\a &= \frac{3}{10} - \frac{\sqrt{69}}{10}\end{aligned}This yields the following solutions. a=3106910,b=197706970\begin{aligned}a = \frac{3}{10} - \frac{\sqrt{69}}{10},\,b = - \frac{197}{70} - \frac{\sqrt{69}}{70}\end{aligned}Substitute 310+6910\frac{3}{10} + \frac{\sqrt{69}}{10} for aa in 7b1=a217 b - 1 = a - 21 and solve.7b1=20710+69107b=19710+6910b=19770+6970\begin{aligned}7 b - 1 &= - \frac{207}{10} + \frac{\sqrt{69}}{10}\\7 b &= - \frac{197}{10} + \frac{\sqrt{69}}{10}\\b &= - \frac{197}{70} + \frac{\sqrt{69}}{70}\end{aligned}This yields the following solution. a=310+6910,b=19770+6970\begin{aligned}a = \frac{3}{10} + \frac{\sqrt{69}}{10},\,b = - \frac{197}{70} + \frac{\sqrt{69}}{70}\end{aligned}