In the equations 8x - 9y = -21 and 2x + 5y = 31, (x,y) equals ?
When you have an equation with two variables, like x and y, it means there are two unknown values that we need to figure out. These variables represent numbers we need to solve for. Typically, you will need two equations to solve for both variables. To do that, isolate one of the variables in one of the equations, like x, and then replace that variable in the other equation with the value it representsFor example, if you have the equations 2x + 3y = 14 and x - y = 2
Isolate the x in the second equation by moving y to the other side (i.e., x = y + 2)
Substitute this expression for x in the first equation (i.e., 2(y + 2) + 3y = 12)
Simplify and solve for y (i.e., 2y + 4 + 3y = 14 => 5y + 4 = 14 => 5y = 10 => y = 2
Substitute this value of y back into the other equation (i.e., x - 2 = 2 => x => 4)
