Question

-2(x-9)+5(x-4)=25;4(5-n)-3(2n+7)=0;

Answer 1

Пошаговое объяснение:

-2x+18+5x-20=25

-2x+5x=25-18+20

3x=27

x=27/3

x=9

20-4n-6n-21=0

-4n-6n=21-20

-10n=1

n=1/(-10)

n= -(1/10)

Answer 2

Let's solve these equations step by step.

1. Solve the first equation: -2(x-9) + 5(x-4) = 25

Distribute the constants on the left side of the equation:

-2x + 18 + 5x - 20 = 25

Combine like terms:

(5x - 2x) + (18 - 20) = 25

3x - 2 = 25

Add 2 to both sides of the equation:

3x - 2 + 2 = 25 + 2

3x = 27

Now, divide both sides by 3 to isolate x:

3x/3 = 27/3

x = 9

So, the solution to the first equation is x = 9.

2. Solve the second equation: 4(5-n) - 3(2n+7) = 0

Distribute the constants on both sides of the equation:

(4 * 5 - 4 * n) - (3 * 2n + 3 * 7) = 0

20 - 4n - (6n + 21) = 0

Now, distribute the negative sign on the right side:

20 - 4n - 6n - 21 = 0

Combine like terms:

(20 - 21) - (4n + 6n) = 0

-1 - 10n = 0

Add 1 to both sides of the equation:

-1 + 1 - 10n = 0 + 1

-10n = 1

Now, divide both sides by -10 to isolate n:

-10n / -10 = 1 / -10

n = -1/10

So, the solution to the second equation is n = -1/10.