6x-5y=21 and 2x+3y=19. find x and y. please teach me how to solve this kind of equation.?

When you have 2 unknowns in these equations, it's important to make the unknowns to 1. eg. (1) 6x-5y=21 and (2) 2x+3y=19 from (1), let's make x as the subject formula 6x=21-5y x=(21-5y)/6 (let's name this eqn 3) Substitute eqn (3) into (2) 2[(21-5y)/6] + 3y =19 Now, you only have one unknown that is y. Solve y and substitute it into eqn (1) to get x. Voila!

6x - 5y = 21 2x + 3y = 19 answer let say 6x - 5y = 21 is equation 1, and 2x + 3y = 19 is equation 2 if we x3 the equation 2, it will be 3(2x + 3y) = 3(19) we get 6x + 9y = 57 and let say it is equation 3 if equation 3 minus equation 1, 6x + 9y = 57 - (6x - 5y = 21) -------------------- 0 +14y = 36 so, 14y = 36 y = 36/14 y = 18/7 then we replace the value of y = 18/7 into the equation 1 6x - 5(18/7) = 21 6x - 90/7 = 21 6x = 90/7 + 21 6x = (90 + 147)/7 6x = 237/7 x = 237/(7 x 6) x = 79/(7 x 2) x = 79/14 hope it will help you

just get y in one of the equations....for a definite explanation i'll use 6x-5y=21, where y is, y=(21-6x)/5 substitute y in terms of x in the second equation to solve for x. 2x + 3/5(21-6x) = 19 2x + (63-18x)/5 = 19 10x + 63 - 18x = 95 -8x = 95-63 x = -32/8 x = -4 (answer) substitute the value of x in the first equation. 6x - 5y = 21 6(-4) - 5y = 21 -5y = 21+24 y = -45/5 y = -8 (answer) i hope this helps a lot......

18x - 15y = 63 10x + 15y = 95--------ADD 28x = 158 x = 158/28 = 79/14 79/7 + 3y = 19 3y = 133/7 - 79/7 3y = 54/7 y = 18/7 x = 79/14 , y = 18/7

Okay Here is the way to do it using that method. Your tryng to find the LCM . SO lets do it for x. FInd the LCM of 6 and 2. It would be 6. SO, lets multiply the 2nd equation by -3. That gives you -6x-9y=-57. SO adding both equaTIONS, CANCELING OUT THE X, that gives you -14y=-36, or y=-36/-14 = 36/14. And x=(21+((36/14)*5))/6.

In these kinds of equations, there are many ways to find x & y. One simple method is to solve using your method - First make the value of either x or y equal in both equations by multiplying the whole equation by some number.i.e. 6x -5y=21 and 3{2x+3y=19} will make the value of x equal in both cases. The new equations would be 6x -5y=21 and 6x+9y=57 which you can easily solve by subtracting the former from the latter. This process is called elimination method.

x= 21/6+5y/6 y=19/3-2x/3 right??

6X-5Y=21 2X+3Y=19 These are called simultaneous equations.we solve them by elimination; substitution; graphically or matrix method. i'll use elimination method. i'll eliminate the x. i.e 6x-5y=21 3(2x+3y=19) 6x-5y=21 6x+9y=57 ----minus equation 2 from wquation 1 we have now; 14y=36 y=18/7 from equation 2; 2x=19-3(18/7) x=38/7

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