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

Related Maths GCSE answers

All answers ▸

The Diagram shows the Triangle PQR. PQ = x cm. PR = 2x cm. Angle QP^R = 30 degrees. The area of the triangle PQR = A cm^2. Show that x = (Squared Root){2A


How do you find the turning point of a quadratic equation?


Solve the simultaneous equations: 6x - 5y = 17, 3x + 8y = 10


There are 10 boys and 20 girls in a class. The class has a test. The mean mark for all the class is 60. The mean mark for the girls is 54. Work out the mean mark for the boys.