Given:
15x - 20y = -1
15y = 2 + 5x
Then:
15x -20(2 + 5x)/15 = -1
∴15x -40/15 - 100x/15 = -15/15
∴225x/15 - 100x/15 = 40/15 - 15/15
∴125x = 25
∴x = 1/5
Check:
15(1/5) - 20(1/5) = -1
∴3 - 4 = -1
∴-1 = -1
Chat with our AI personalities
x+y=5
by elimination,substitution or through the matrix method.
If: x+y = 4 and y = 2x+1 Then: 4-x = 2x+1 => 3 = 3x => 1 = x So by substitution: x = 1 and y = 3
The substitution method in mathematics is a technique used to solve systems of equations by isolating one variable and substituting it into the other equation. The method is not attributed to a single inventor, as it has been used by mathematicians for centuries. The concept of substitution in algebra can be traced back to ancient civilizations such as the Babylonians and Greeks, who used similar methods to solve mathematical problems.
-2