Question

5x - 4y = 4 x + 2y = 8

Answer 1

Answer:

{2.86, 2.57}

Step-by-step explanation:

To solve a system of equations, you would want to use the eliminaton or the substitution method. These methods are sujective, so use the one you like the most. I will show you both methods to get a better understanding.

Elimination:

To do the elimination method, you will need to find common terms (x or y) and have an opposite each (-5 or 5). Look at the first equation. Now look at the second equation. Which equation do you think would need to be changed in order to receive a -5 and 5? The second equation. Multiply the second equation by -5. This would give you -5x-10y=-40. Now you are ready to add the two equations together. Notice how the x's cancel out. this leaves you with -14y=-36. To get the y by itself, you will need to divide each side by -14. You will soon get y=2.57. YOU ARE NOT FINISHED. You will need to get the x value. Take one of the equations and add substitute the y into it. Looking at both equations, the second one will be easier to substitue. By adding y into the mix, you will get x+5.14=8. Subtract 5.14 by both sides and you will get x=2.86. You solution should by {2.86, 2.57}.

Substitution:

to do the substitution method, you will look for a variable that is isolated from a coefficient. As seen in the second equation, x is isolated. Use the second equation to isolate x on one side of the equal sign. You would end up with x=8-2y. Substitute the x into the first equation. This would look somethign like this: 5(8-2y)-4y=4. Multiply what is needed. You should end up wiht 40-10y-4y=4. Combine the like terms of the y: 40-14y=4. Subtract 40 from both sides. You should end up with -14y=-36. DOESN'T THIS LOOK FAMILIAR!!! To get the y by itself, you will need to divide each side by -14. You will soon get y=2.57. You will need to get the x value. Take one of the equations and add substitute the y into it. Looking at both equations, the second one will be easier to substitue. By adding y into the mix, you will get x+5.14=8. Subtract 5.14 by both sides and you will get x=2.86. You solution should by {2.86, 2.57}.