X - y = 4 (1) 2x + y = 9 (2) We need to solve for x and y.
Let's find the algebraic value of x using the equation (1): x-y = 4 add y in both sides x-y+y = 4+y x = 4+y
Now let's using this value instead of x in the equation (2): 2x + y = 9 2(4+y) + y = 9 8 + 2y + y = 9 3y + 8 = 9 Subtract 8 from both sides 3y + 8 - 8 = 9 - 8 3y = 1 divide both sides by 3 (3y)/3 = 1/3 y=1/3
Let's use the value of y to find the value x using the equation (1) x - y = 4 x = y+4 x = 1/3 + 4 x = 13/3
So x = 13/3 and y = 1/3
Let's recheck the answers (very important): x - y = 13/3 - 1/3 = 12/3 = 4 (correct) 2x + y = 2*(13/3) + 1/3 = 26/3 + 1/3 = 27/3 = 9 (correct) The answer has been approved.
