x+30 = 3x-50 x-3x = -50-30 -2x = -80 x = 40
4x + 10 + 3x = 40 - 3x 4x + 10 + 3x + 3x = 40 20x = 40 x = 2
5
2x+17=6x-23 23+17=6x-2x 40=4x x=40 / 4 therefore x=10
6x-52 = 4x+40 6x-4x = 40+52 2x = 92 Answer: x = 46
10 - 3x = x - 2x + 40 10 - 3x = - x + 40 10 - 40 = 3x - x -30 = 2x -15 = x
2x+9 = 49-3x 2x+3x = 49-9 5x = 40 x = 8
7. 8x-40=2x+2 4x-20=1x+1 3x-21=0 3x=21 therefore x=7
y=16 x= -4
x+30 = 3x-50 x-3x = -50-30 -2x = -80 x = 40
3x + 2x - 20 = 180 5x - 20 = 180 Add 20 to both sides: 5x = 200 Divide both sides by 5: x = 40
4x + 10 + 3x = 40 - 3x 4x + 10 + 3x + 3x = 40 20x = 40 x = 2
x + 3x = 40 4x = 40 x = 10.
x^2+2x+40 = x^2-x+190Subtract x^2 from both sides2x+40 = -x+190Add x to both sides3x + 40 = 190Subtract 40 from each side3x = 150Divide both sides by 3x = 50
5
Add the two equations you get 5y = 60 so y = 12 and x = 2
-4x2 + 6x + 40 = 0 ∴ -2x2 + 3x + 20 = 0 ∴ -2x2 - 8x + 5x + 20 = 0 ∴ -2x(x + 4) + 5(x + 4) = 0 ∴ (5 - 2x)(x + 4) = 0 ∴ x ∈ {5/2, -4}