The solution (x, y) is (4, 2/7)
Step-by-step explanation:
Addition method is the same as elimination method
9x + 7y = 38 ...(1)
4x - 7y = 14 ...(2)
Using addition method:
Let's eliminate y. To do this we need to ensure the coefficient of y in both equations are the same. wehave 7 in both but the signs are different.
Since they have different sign, we'll add equation 1 and 2:
9x + 4x + 7y + (-7y) = 38 + 14
13x + 7y - 7y = 52
13x = 52
divide both sides by 13:
13x/13 = 52/13
x = 4
substitute for x in equation 2:
4(4) - 7y = 14
16 - 7y = 14
16 - 14 = 7y
2 = 7y
y = 2/7
The solution (x, y) is (4, 2/7)
To check:
using (1): 9x + 7y = 38
9(4) + 7(2/7) = 38
36 + 2 = 38