Note: the "e" on the first row fifth key, does, in fact double as Euler's constant. Try typing in 1*e= using that e.
1/3 = 4/12 so 1/3 - 11/12 → 4/12 - 11/12 → -7/12
.
Replace y in the first equation by the right hand side of the second equation:
2x + 3(3x + 15) = 1
2x + 9x + 45 = 1
11x + 45 = 1
11x = 1 - 45
11x = -44
x = -44/11
x = -4
Put this back into y = 3x + 15
y = 3(-4) + 15
y = -12 + 15
y = 3
I should have written: solve(y-ln(x),x) above. (I.e. entered a minus sign, not an equals sign)
You can also type in something like: solve(y=ln(x),x) and press equals to get:
The calculator here will solve some algebraic equations, and will give information about integral so and derivatives. For example, if you enter: x^2-3 and then press the equals sign, you get the following:
As below:
Use the calculator on the home page here:
Examples:
Round 5.4 to the nearest integer: 5
Round 5.7 to the nearest integer: 6
Round 5.674 to two decimal places: 5.67
etc.
Interesting. It calculates for ages, then gives up the ghost!!
Mathcad also fails to find a solution when presented with the same two equations.
If you replace the first r^n by 243r, both Mathcad and Wolfram Alpha find the solution immediately.
+33667 
