solve the simultaneous equations: 2x-3y = 16 and x + 2y = - 6
First we need to subtract a variable from another to eliminate a variable from both equations. To do this we need to make either the X value the same or the Y value the same.We can do this by multiplying the second equation by two giving us 2X + 4Y = -12Now we have a 2x in the first equation and the second.2x - 3y = 162x + 4y = -12 Now subtract the second equation from the first. (take care with the negative values-7y = 28Next divide both sides by -7y= 28/-7 = -4So now we have our y value (-4)Next, substitute the y value into one of the equations.x + 2y = -6x + 2(-4) = -6 Expand out the bracketx - 8 = -6 Add 8 to both sidesx = 2SOLUTION: X = 2 Y = -4
DR
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