Q. Find the solution of the system of equations.−5x+15yx+5y=20=−12
Substitution or Elimination Method: Let's start by solving the system of equations using the substitution or elimination method. The elimination method seems more straightforward since the coefficients of y are multiples of each other. We will multiply the second equation by 3 to make the coefficients of y in both equations equal.Multiplication: 3(x+5y)=3(−12)Calculation: 3x+15y=−36
Multiplication and Calculation: Now we have a new system of equations:{−5x+15y=203x+15y=−36We will add both equations to eliminate y.Addition: (−5x+15y)+(3x+15y)=20+(−36)Calculation: −5x+3x+15y+15y=20−36Simplification: −2x+30y=−16However, we made a mistake in simplification; the y terms should cancel out, not add up.