To solve the system of equations by elimination, we need to eliminate one variable by adding or subtracting the two equations. Let's eliminate the variable "y" by subtracting the first equation from the second equation:
(7x + 5y) - (2x + 5y) = 5 - (-20)
This simplifies to:
7x + 5y - 2x - 5y = 5 + 20
Combine like terms:
5x = 25
Divide both sides by 5:
x = 5
Now, substitute this value of x back into one of the original equations to solve for y. Let's use the first equation:
2x + 5y = -20
2(5) + 5y = -20
10 + 5y = -20
Subtract 10 from both sides:
5y = -30
Divide both sides by 5:
y = -6
Therefore, the solution to the system of equations is x = 5 and y = -6.
Solve the systems of equations by elimination
2x+5y = -20
7x + 5y = 5
1 answer