Question #f9676

1 Answer
Sep 2, 2017

You could use substitution (y = 1 - x) or linear systems.

Explanation:

Write the two equations as a linear system. Use algebraic properties to find the unknowns. A linear system can be solved as long as there are at least as many independent equations as there are variables.
2x = 5y
x + y = 1 First, get all of the variables on one side:
2x - 5y = 0
x + y = 1; Now multiply the second equation by 5d and add it to the first one:
2x - 5y = 0
5x + 5y = 5

7x = 5; x = 5/7; Substitute this value back into the first equation to find the 'y'.
2(5/7) = 5y; (2/5)(5/7) = y; y = 2/7
CHECK by putting both values into the second equation:

x + y = 1 ; 5/7 + 2/7 = 1 ; 1 = 1 CORRECT!