Solve the simultaneous equations, giving each value in your solution to 2 decimal places.

[tex]
\begin{cases}
e^{2y} - x + 2 = 0 \\
\ln(x + 3) - 2y - 1 = 0
\end{cases}
[/tex]



Answer :

To solve the given system of simultaneous equations:
[tex]\[ \begin{cases} e^{2y} - x + 2 = 0 \\ \ln(x + 3) - 2y - 1 = 0 \end{cases} \][/tex]
we need to find the values of [tex]\( x \)[/tex] and [tex]\( y \)[/tex] that satisfy both equations.

1. Rewrite the first equation:

[tex]\[ e^{2y} - x + 2 = 0 \implies e^{2y} = x - 2 \][/tex]

2. Rewrite the second equation:

[tex]\[ \ln(x + 3) - 2y - 1 = 0 \implies \ln(x + 3) = 2y + 1 \][/tex]

3. Express [tex]\( y \)[/tex] from the logarithm equation:

[tex]\[ \ln(x + 3) = 2y + 1 \implies 2y = \ln(x + 3) - 1 \implies y = \frac{\ln(x + 3) - 1}{2} \][/tex]

4. Replace [tex]\( y \)[/tex] in the exponential equation:

Substitute [tex]\( y = \frac{\ln(x + 3) - 1}{2} \)[/tex] into [tex]\( e^{2y} = x - 2 \)[/tex]:

[tex]\[ e^{2\left(\frac{\ln(x + 3) - 1}{2}\right)} = x - 2 \][/tex]

5. Simplify the exponential expression:

[tex]\[ e^{\ln(x + 3) - 1} = x - 2 \][/tex]

Using properties of exponents, we can write:

[tex]\[ e^{\ln(x + 3)} \cdot e^{-1} = x - 2 \implies \frac{x + 3}{e} = x - 2 \][/tex]

6. Clear the fraction:

[tex]\[ x + 3 = e (x - 2) \][/tex]

7. Distribute [tex]\( e \)[/tex]:

[tex]\[ x + 3 = ex - 2e \][/tex]

8. Isolate [tex]\( x \)[/tex]:

[tex]\[ x - ex = -2e - 3 \][/tex]

[tex]\[ x(1 - e) = -2e - 3 \][/tex]

Therefore,

[tex]\[ x = \frac{-2e - 3}{1 - e} \][/tex]

9. Calculate the numerical value of [tex]\( x \)[/tex]:

Using the known value:

[tex]\[ x = 4.91 \quad (\text{to 2 decimal places}) \][/tex]

10. Substitute [tex]\( x \)[/tex] back to find [tex]\( y \)[/tex]:

[tex]\[ y = \frac{\ln(4.91 + 3) - 1}{2} \][/tex]

11. Evaluate [tex]\( y \)[/tex]:

Also using the known value:

[tex]\[ y = 0.53 \quad (\text{to 2 decimal places}) \][/tex]

Thus, the solutions to the simultaneous equations are:

[tex]\[ x = 4.91, \quad y = 0.53 \][/tex]

These values satisfy both equations within the given constraints.