If: 4x = x+15 Then: x = 5
3x+7=4x 7=4x-3x 7=x
y = 2x + 15 y = 4x + 7 Substitute the value of y from the first equation into the second: 2x + 15 = 4x + 7 Subtract 2x from both sides: 15 = 2x + 7 Subtract 7 from both sides: 8 = 2x Divide both sides by 2: 4 = x. Replace x by its value, 4, in the first equation: y = 2*4 + 15 = 8 + 15 = 23 So the solution is (x, y) = (4, 23)
(A): 4x + y = 7 (B): 2x - 3y = -7 2*(B) 4x - 6y = -14 Subtract from (A) 7y = 21 Divide both sides by 7: y = 3 Substitute in (A): 4x + 3 = 7 ie 4x = 4 or x = 1 Answer: x = 1 , y = 3
3x2-4x-15 = 0 (3x+5)(x-3) = 0 x = -5/3 or x = 3
4x+7-3x = 15 4x-3x = 15-7 x = 8
4x-1 = 6x-15 4x-6x = 1-15 -2x = -14 x = 7
4x-7=5x-2 x=-5
x = 37 4x - 7 = 141 4x - 7 + 7 = 141 + 7 4x = 148 x = 37
If: 4x = x+15 Then: x = 5
If: 5x = 4x+7 Then: 5x-4x = 7 And: x = 7
3x+7=4x 7=4x-3x 7=x
4x-5=7 4x=12 x=3
4x - 1 = 15 Therefore, 4x = 16 x = 16/4 Therefore, x = 4
x=-7
3x = 7-4x 3x+4x = 7 7x = 7 x = 1
4x - 7 = 1 Therefore, 4x = 8 x = 8/4 x = 2