Answer :

jay40891

Step-by-step explanation:

3x + y = 3

y = 3 - 3x (Bring the 3x to the right hand side)

5x - y = 15

5x - (3 - 3x) = 15 (Replace the y with 3 - 3x)

5x - 3 + 3x = 15 (Expand Brackets)

8x = 18 (Bring numbers to Right Hand Side)

x = 9/4 (algebraic) or x = 2 (estimated)

Hence y = 3 - 3(9/4)

y = - 15/4 (algebraic) or y = -4 (estimated)

brevyn
Solving by substitution means that you solve for one variable, then the other using the solve you made earlier. So if you took the top equation and moved it around a little to get the answer for y, you would get y=3-3x. So joe for the lower equation you can substitute for y, and get the equation 5x-(3-3x)=15. Do some math from there to get 3x=18, so x=6. Now we return to the original top equation and solve for y. If y=3-3x, put in 6 for x and get y=3-3(6), so y=-15. Now you have your answer, the ordered pair is (-15,6) estimated solutions are different.