Solve equations with substitution method
- Task
Let given equations:
3x + y = -1 and 2x - 3y = -19
Solve it with substitution method.
- See related
Julia
<lang julia>function parselinear(s)
ab, c = strip.(split(s, "=")) a, by = strip.(split(ab, "x")) b = replace(by, r"[\sy]" => "") b[end] in "-+" && (b *= "1") b = replace(b, "--" => "") return map(x -> parse(Float64, x == "" ? "1" : x), [a, b, c])
end
function solvetwolinear(s1, s2)
a1, b1, c1 = parselinear(s1) a2, b2, c2 = parselinear(s2) x = (b2 * c1 - b1 * c2) / (b2 * a1 - b1 * a2) y = (a1 * x - c1 ) / -b1 return x, y
end
@show solvetwolinear("3x + y = -1", "2x - 3y = -19") # solvetwolinear("3x + y = -1", "2x - 3y = -19") = (-2.0, 5.0) </lang>
Raku
<lang perl6>sub solve-system-of-two-linear-equations ( [ \a1, \b1, \c1 ], [ \a2, \b2, \c2 ] ) {
my \X = ( b2 * c1 - b1 * c2 ) / ( b2 * a1 - b1 * a2 );
my \Y = ( a1 * X - c1 ) / -b1;
return X, Y;
} say solve-system-of-two-linear-equations( (3,1,-1), (2,-3,-19) );</lang>
- Output:
(-2 5)
Ring
<lang ring> firstEquation = [3.0,1.0,-1.0] secondEquation = [2.0,-3.0,-19.0] getCrossingPoint(firstEquation,secondEquation)
func getCrossingPoint(firstEquation,secondEquation)
x1 = firstEquation[1] y1 = firstEquation[2] r1 = firstEquation[3] x2 = secondEquation[1] y2 = secondEquation[2] r2 = secondEquation[3] temp = [] add(temp,x1) add(temp,-y1) add(temp,r1) resultY = ((temp[1]* r2) - (x2 * temp[3])) / ((x2 * temp[2]) + (temp[1]*y2)) resultX = (r1 - (y1*resultY)) / x1 see "x = " + resultX + nl + "y = " + resultY + nl
</lang>
- Output:
x = -2 y = 5
Wren
<lang ecmascript>var solve = Fn.new { |e1, e2|
e2 = e2.toList for (i in 1..2) e2[i] = e2[i] * e1[0] / e2[0] var y = (e2[2] - e1[2]) / (e2[1] - e1[1]) var x = (e1[2] - e1[1] * y) / e1[0] return [x, y]
}
var e1 = [3, 1, -1] var e2 = [2, -3, -19] var sol = solve.call(e1, e2) System.print("x = %(sol[0]), y = %(sol[1])")</lang>
- Output:
x = -2, y = 5