2y+3y-7y+4=16 -2y=12y=-6Check it-12-18+42+4=16-30+46=1616=16
5y explanaition 5x-5x=0, 0-2y=-2y, -2y+7y=5y
7y + 4 = 5y - 6Subtract 4 from each side:7y = 5y - 10Subtract 5y from each side:2y = -10Divide each side by 2:y = -5
(-4, -1)
x + 7y = 33 (1) --> x = 33 - 7y (1a) 3x - 2y = 7 (2) To solve the simultaneous equations, starts by substituting the value for x found in (1a) into (2): 3(33 - 7y) - 2y = 7 99 - 21y - 2y = 7 -23y = -92 y = 4 Now substitute this value for y into (1a) and solve for x: x = 33 - 7(4) x = 33 - 28 x = 5 Therefore these equations have the solution x = 5, y = 4
7y + 2y = 9y 7y * 2y = 14y^2
2y+3y-7y+4=16 -2y=12y=-6Check it-12-18+42+4=16-30+46=1616=16
5y explanaition 5x-5x=0, 0-2y=-2y, -2y+7y=5y
5y+8=7y 2y=8 y=4
13x10yx7+2y 13
7y - 6 = 5y - 147y - 5y = 6 - 142y = -8y = -8 ÷ 2y = -4
10y = 9y + 4, so y = 4
-3
x+7y=39
7y + 4 = 5y - 6Subtract 4 from each side:7y = 5y - 10Subtract 5y from each side:2y = -10Divide each side by 2:y = -5
(-4, -1)
x + 7y = 33 (1) --> x = 33 - 7y (1a) 3x - 2y = 7 (2) To solve the simultaneous equations, starts by substituting the value for x found in (1a) into (2): 3(33 - 7y) - 2y = 7 99 - 21y - 2y = 7 -23y = -92 y = 4 Now substitute this value for y into (1a) and solve for x: x = 33 - 7(4) x = 33 - 28 x = 5 Therefore these equations have the solution x = 5, y = 4