Simultaneous Equations


Introduction


Two unknowns require two simultaneous eqns

Simultaneous Equations


4x + 2y = 8    (1)

2x - 5y = 10    (2)

(2) × 2 gives

4x - 10y = 20    (3)

(1) - (3) gives

12y = -12

so

y = -1

Substituting this into (1)

4x + 2(-1) = 8

4x + -2 = 8

4x = 10

x = 2.5

check that these values of x and y actually satisfy the two given simultaneous equations (witha all algebaraic equations, you can always check to see whether you have the right answer).