The solution equation: (x + 1) (x + 2) (x + 3) (x + 4) = 120

The solution equation: (x + 1) (x + 2) (x + 3) (x + 4) = 120

From the original equation, (x2 + 5x + 4) (x2 + 5x + 6) = 120. Let x2 + 5x = y, then (y + 4) (y + 6) = 120. That is Y2 + 10y-96 = 0. So (y-6) (y + 16) = 0. The solution is y = 6 or y = - 16. When y = 6, X2 + 5x = 6, then (x + 6) (x-1) = 0. The solution is X1 = - 6, X2 = 1; when y = - 16, X2 + 5x = - 16, that is x2 + 5x + 16 = 0, the equation has no solution

Solve the equation 25% x + 40% x = 5.2 (1-75%) x = 36 120-25% x = 100 x / (1-24%) = 1.14

25%x+40%x=5.2 0.65x=5.2x=8（1-75%）x=36 0.25x=36x=144120-25%x=100 0.25x=120-1000.25x=20x=80x/(1-24%)=1.14x=1.14x0.76x=0.8664

Solution equation, (x + 25%) × 2 = 120% x-x = 24

(x+25%)×2=120
（x+0.25）*2=120
x+0.25=60
x=59.75
120%x-x=24
(1.2-1)x=24
0.2x=24
x=120

Solving equation 5x * 10 / 3 + 4x * 10 / 3 + 120 = 5x + 8

x=-112/25